Who says that? History books say it's because Weimar Germany was a horror show and Germans were still smarting after Versailles.
In other words, Hitler was the result of not completely destroying Germany as a military power, while still bruising its ego enough to make for the biggest chimp-out Europe saw since the 30YW.
People and history books like to gloss over the fact that Weimar Germany was a liberal/Left social utter shitshow. I don't like using "degeneracy" as a definition because typically it's used with religious reasoning behind it, but that's basically what was happening back then.
One of the main motivations for a lot of Germans behind their support of Hitler is because he (in reality falsely) offered himself as a way out from all the socially degenerate shit the Weimar Republic had plunged itself in to (which a lot is currently mirrored in present day culture, sadly enough).
Of course there were other, well documented reasons why people wanted him in, such as being anti-Communist, reforming the economy, pandering to their bigotry versus Jews, et cetera, but stopping what was basically social decay and "progressivism" were two of them which motivated a lot of everyday Germans to support him.
While Hitler was, ironically, Far Left (and not Far Right as many people like to say these days, especially when trying to divorce the modern Left/Far Left from historical connotations and portraying anyone against them as being "evil Far Right"), it honestly wouldn't shock me if in the next ten, twenty years, a lot of countries in the West end up having more and more "Far Right" values taking over... Which is obviously a complete mixed bag and another shit show in itself, but again if it's a way out of the current clusterfucks going on, people would take it.
Oh boy are you out of the loop, "And for no reason at all, people voted Hitler into power" is a semi-common meme.
This too. It's a meme with truth behind it.