It always was an architectural movement influenced by political motivations: reaction to nostalgic architecture of the 40s and low cost social housing influenced by socialist principles. It was pretty much imposed in uk by the government after the war and created a series of terrible housing estates in which crime proliferated (because they are impossible to police). Brutalist aesthetic became a thing long after, as an acquired taste.
Also tbh when people think of brutalist aesthetics they usually think of the same few grand building (like the Barbican Centre in London) that costed a lot of money, are constantly maintained to this day and are kind of an one-off. The day to day reality of brutalism, unfortunately, are huge blocks of high density houses in terrible maintenance conditions (reinforced concretes dissolves easily and leaves leaks and rusty rebar exposed) that cannot be replaced anymore.
Also tbh when people think of brutalist aesthetics they usually think of the same few grand building (like the Barbican Centre in London) that costed a lot of money, are constantly maintained to this day and are kind of an one-off. The day to day reality of brutalism, unfortunately, are huge blocks of high density houses in terrible maintenance conditions (reinforced concretes dissolves easily and leaves leaks and rusty rebar exposed) that cannot be replaced anymore.