I think the downfall of brutalism is that the architects were working on the wrong scale. Looking at these photos, some of these buildings look fantastic from afar, but the close up photos reveal the poor livability of the designs and materials. I know it's subjective, but I've just never felt welcomed by brutalism's buildings.

One of the more telling examples of that is a building near me, where the street-front vegetation is done in these huge concrete planters suspended by huge concrete pillars. Sure you can see if from a block over, but at street level, you can't. It's almost like they are holding it over your head to tease you.