They call it "Brutalism" for a reason. Soviet buildings often look like flak towers.
Though the common modern understanding of it does lend itself to 'brute'. I think one of the real issues was the post WWII era of 1950s to 1980s was a time of focus on low cost construction with an overconfidence in the forgiving nature of concrete combined with a fair amount of corruption in the factory supplied components - at least in the UK which I'm more familiar with.
It can be done well, and I point to the Barbican in London as an example. With better construction techniques it can last a lot longer with less maintenance cost.
English brute and French brut (raw) both seem to come from the Latin brutus.
https://www.barbican.org.uk/our-story/architecture/our-build...
To me, this looks more like an East Berlin apartment building for the Communist Party elites. Not as ugly as the workers' buildings, but that's not saying much.
The brutalist-does-not-mean-ugly architecture I usually point to is the Washington Metro.
> Brutalism is an architectural style of the 20th century that mainly uses concrete as a building material. The term "brutalism" comes from the French expression "béton brut", which means "raw concrete".
https://industrialkonzept.com/blogs/magazine/beton-brut-berl...