You can't really 'build' a character which excels at any one thing, every character ends up a master of all unless you 'really' go out of your way to stop it.
Happens due to a couple of reasons.
1: You have unlimited levels, inevitably you become good at everything, Fallout 2 had this issue to some degree but you couldn't endlessly increase SPECIAL in FO2.
2: Perks are a replacement for skills, except you cannot rush perks, they are level-gated. Want to be a master lockpick at level 10 like you could in FO3/NV? Nope! Not happening here!
3: Because there's no skill checks for 99.99% of the game, every single little aspect of the game comes down to 'shoot things, sneaking or not'. This means there's really only two viable builds, shooty man and sneaky shooty man. But because the DPS boosting perks are level gated, you will always have spare perk points to become a master at every other element that happens on occasion.
I think your definition of RPG is a bit straightjacketed. Compare Fallout 4 to, say, Mass Effect (and a few other games, but I'll pick ME as the core example).
1. In Mass effect, the only things you're locked out of are combat powers, and while you have to level those powers to make them stronger and acquire new bonuses, starting out you're already highly combat effect....and that's how your combat skills work in 4 as well. On the non-combat side, Shepard can always hack through anything, pick any lock, talk down any person, right from the start. Shepard is good at everything as well. Furthermore, this isn't some new change, 3 and NV both let you build a character with maxed out skills and all the must have perks with
trivial ease.
2. Level gating abilities is the
norm for RPGs, fallout was unusual in that it did otherwise. And frankly, dumping skill points was the right call. Boosting combat skills gave next to no discernable bonus as you leveled (oh, sure, over time it would help, but each individual level up was near meaningless), and boosting science, lockpick, etc was even worse, as you got no real bonus until you hit a certain threshold, outside of a tiny handful of skill checks. And the functional difference between "has 45 points in science" and "has rank 3 science perk" is nonexistent.
3. It's an RPG where guns are the primary combat system, of course the main gameplay system is guns (or melee, if you want). In contrast ME also has only two character builds, cover shooting guy and vanguard. I admit the DPS perks and overall bullet spongeness was a bad design, but an RPG with a bad combat system
cough KOTOR
cough is still an RPG. And it's not like 3 or NV where packed full of skill checks either, the main form of gameplay there was also just shooting people.
A game where you can get 10+ in every SPECIAL AND every perk, can hardly be called an RPG. You could get 100 skill in FO NV but you had to try for it with the right build and foreknowledge.
Maxing out a character in NV and 3 was trivial, the only way it could possibly be tricky is if you wanted 100 in every single skill and weren't will to have a combat skill or two you never used left low. Yeah, maybe you had to do some basic math to figure out how many skill points you'd need per level or what perks to take, but planning a character build is a basic part of playing an RPG.
Also, ya know, character backstory, we KNOW who the player character is, we cannot choose his role in the world, you can't even be the leader of a faction without feeling like a subordinate.
A good RPG goes "Name your character, think on what he's supposed to be, and fill in the rest with imagination!", FO4 goes "You are a soldier of a lawyer based on your sex, you even have a canonical name which you can ignore, oh and you're ALWAYS a good shot".
Ok, and in Mass effect you have a choice of 3 backstories that have next to no impact, you are a colonist/spacer/earthborn and oh and you're always a good shot". In KOTOR you have no choice about your backstory, in Elex you have no choice about your backstory, in dragon age your race picks what your backstories can be. And frankly, Fallout 4 does way less than any of those (and those aspects of your character's past come up only marginally more often then they do in ME). It's also a little funny to complain that the male PC is established to be good shot and was a soldier, because usually that would be a good example of a game justifying a character's baseline skillset.
This is how many CRPGs have done things for
decades, include some of the most celebrated examples of the genre, saying any game that doesn't let you start as a total blank slate is "not an RPG" is just absurd. Tabletop RPGs can afford that, expensive CRPGs where every option you add means more coding time, more lines of dialogue to record, less connection to the ongoing story, etc....no, that's just not going to be possible all the time.
NV had weapon sway if you lacked strength checks with weapons or lacked skill to use them, a 1 strength pansy (Described as "Wet Noodle in NV) can pick up a minigun and fire with flawless accuracy in FO4.
Yes, and when NV did that it was bad, it's not fun to start out with your basic ability to shoot straight crippled because some random numbers are too low, not to mention being totally nonsensical. What, did the Courtier just not learn anything about firearms handling for decades and then over the course of a few weeks become the greatest gunslinger in the country (and don't say "bullet to the head", nothing in the game suggests that your abilities are impaired by getting shot)? And also they can be a crack shot with a rifle, but trying to shoulder and aim a
laser rifle, well that's a totally different skillset there, you have to put points somewhere else if you want to be able to hold one of those things steady as you shoot, because reasons.
What 4 does it leaves your basic aim unaffected, and then gates more advanced and capable weapons (or rather the mods to craft them), behind levels. What is the functional distance between needing a lot of points in the Gun skill to be able to accurately fire a sniper rifle, and needing a high level Guns perk to be able to build a sniper rifle with the proper barrel, caliber, scope, etc?
Fallout 1 has the only rule that you are a vault dweller. Your purpose in the vault, your training, your age, appearance, all of it is completely up to you. FO4 has canonical protagonists. Nate and Nora.
Fallout 4 does not have canon protagonists, it has default names and appearances which you are free to change as much as you like.
NV does not have a set background aside from that you were a courier for some undisclosed period of time. You could have any name, natural skillset, etc. Also factor in the two bullets to the brain could do any number on your personality or behaviors.
There's absolutely no canon evidence whatsoever that getting shot changed your personality in NV. Your character remembers their past, remembers their history, they would 100% notice if they had changed after getting shot.
I'm also uncertain why "you were a courier for some undisclosed portion of time" is acceptable material to establish for a PC, but "you were a soldier for some undisclosed portion of time" is not. Given how much you complain about 4 giving you good aim from the start, I would think them establishing that male PC was a soldier would be a good thing, it justifies that existing skillset.
Additionally, NV is actually the worst of the modern fallout games when it comes to railroading your character into following the story. "Find your dad, the only family you have left after he left and the vault fell apart", fairly compelling, makes sense that your PC would do that. "Find your abducted son", that's even stronger.
NV, on the other hand? "Find the guy that shot you, because...uh, you just really want to, I guess. And also follow this exact trail to find him or the wildlife will murder you, because we said so." What if I decide that hey, getting robbed is part of the risk, better count my blessings and move on? What if I decide to just go back to work and get the next package? Oh, sorry, I don't get to do that, I must get my revenge, because Obsidian decided that for me.
Nate/Nora becoming a psychopath makes very little sense, it makes a lot more sense in FO1-2-NV where we have absolutely no idea what they were doing before we took control of them.
It makes no sense in any fallout game to play as a psychopath, but it makes substantially
less sense in 1 and 2. We don't know what the Vault Dweller and Chosen One's lives were like before the game, but we know where they lived, and we know that small, tightly knit societies, like those of vaults and tribes, are generally not cool with wildly anti-social behavior.
Fallout 4 basically forces you to play either a good guy or a sarcastic jerk who still does everything anyways.
And Mass Effect forces you to be either a goodie two shoes paragon or a hardass renegade who still does everything anyways. It's still an RPG.