>I think the biggest problem with them is that the minute you stop maintaining things like gardens in contrast to the concrete and let it get dirty and scarred, it looks apocalyptic and stressful very quickly.

There's a trend in some Eastern European countries to paint older brutalist concrete buildings as a cost-effective measure to reduce concrete spalling and do thermo-modernization. It's actually pretty amazing how much nicer some of these buildings look even with just a uniform white paint job (others involve more color).

Architects seem to be largely opposed, seeing it as an erasure of the material honesty that brutalism was supposed to represent, but IMHO it suggests that a lot of the core issue with these designs wasn't the shape or creativity of the buildings themselves but just the way the concrete look quickly aged.