I'd say 'sometimes' rather than 'often'. But the underlying reason for this is still the same – cheap construction, poor maintenance. And of course those are the unpopular buildings. But there's nothing inherent to brutalism that means buildings have to be constructed like that.

My favourite examples of this kind of thing are the 'New Towns' in the UK. These were build in the late 40s through to the mid 60s to deal with overspill from cities. Towns like Cumbernauld and Livingston in Scotland were designed to be very human-focused – easy to walk through, segregated road systems, distinct districts with local services, central civic centres and so on. A genuinely utopian vision of the future, in some respects.

The problem is that shoddy construction and poor maintenance made living conditions unacceptable. Demographic changes and the mass overspill from cities made for less cohesive communities – segregated underpasses for example became sites of violent crime.

I think that in most cases the reasons for certain brutalist developments being unpopular is down to causes distinct from the architecture – and I think it's a mistake to conflate the issues. Though it does explain the unpopularity.

I think blaming this on cheap construction and poor maintenance (true as it may be) is missing the mark.

Blaming it on brutalism is also, IMO, missing the mark.

The core blame here lies in the fact that these complexes are built in the style of the Radiant City, which encouraged monolithic buildings surrounded by "parkland" and public spaces. It was imagined as a utopian balance between urban and rural - everyone living in a tower would have ready access to ample public space.

In reality of course these projects are largely defined by their emptiness, and these public spaces unused (and consequently, unsafe). The shoddy construction and maintenance surely didn't help, but IMO was not the root of the problem - we have seen more traditionally built communities fall into disrepair but never reach the level of isolation and segregation we see in these buildings.

It's just coincidence that brutalism reached its popular height along with Radiant City urban planning.

More importantly, even though brutalism has fallen out of vogue, Radiant Cities have not - most new American urban cores (particularly in the Midwest/West) are built around this philosophy still, and the net result has been the gutting of once tight-knit neighborhoods and replacing them with soaring towers and empty sidewalks (see: Belltown in Seattle). Brutalism may be gone, but 50 years from now someone will write another article about this exact phenomenon, with glass-clad apartment buildings in their place.