Thing is, the Jedi Council were in a catch 22 with Anakin.
He was too old and he was too emotionally attached. They weren't wrong.
However, he was a powerful Force-user, Chosen One or not (spoiler: He was, but not in the way they wanted), and they knew that if they just let him go, he'd be snapped up by unsavoury elements in a heartbeat (such as the then hypothesized Sith returning).
Plus, one of their best, QGJ, was willing to say "fuck you" to them and train him of his own accord.
They were fucked from the get-go.
My take on it is that Qui-Gon thoughtlessly set Anakin up to fail from the start. If you take all the dialogue from TPM "as is":
1. Qui-Gon straight up promises Anakin that he's *going* to be a Jedi, no qualifiers and no mention of any issues. Granted, Anakin is a little kid, but it's absolutely clear that he's very intelligent, he's had to grow up terribly fast because of slavery, and he is absolutely *not* the sort of sheltered kid who "needs" to have reality sugar-coated.
2. When they get to Coruscant, Anakin suddenly finds out that no, he *doesn't* get to be a Jedi as promised, he's going to be judged by a Council of Masters -- a word that has
absolutely huge implications to a slave. So
no shit Anakin is scared when he appears before the Council-- he's had the rug yanked out from under him in a very cruel way,
and he most likely thinks that he's going to be sent back to slavery since Qui-Gon didn't bother explaining otherwise.
3. Qui-Gon did a
shitty job of actually presenting Anakin to the Council, as he goes all starry-eyed over the dubious Chosen One prophecy and makes
absolutely no attempt to highlight Anakin's positive characteristics. Like pointing out this
desperately poor little kid literally put his life and his
only meaningful possession on the line to help the Jedi complete their mission even though they offered him
nothing in exchange? Qui-Gon chooses to double down on his apparently trademark antagonizing the Council by declaring that he's going to do whatever the fuck he sees fit without condescending to explain to anyone else, even though bringing up Anakin's positive traits would
directly address the Council's legitimate concerns.
3a. For that matter, the Council's concerns were clearly amplified by the fact that Qui-Gon just brought up the whole Sith encounter thing. It would have been much more sensible for him to secure Anakin's future *before* bringing up the bad news?
4. Given that Anakin at age 9 was well within the Initiate age range, there was also
literally no reason for Qui-Gon to implicitly dump Obi-Wan on the spot, and that dovetails in a *very* ugly way with the history established by the Jedi Apprentice books, in which Qui-Gon has in fact
on multiple occasions abandoned Obi-Wan.