Brutalism was designed to expose the functionality of the way everything was built. We'd been using Portland cement for a few decades at that point, but we always hid it behind facades meant to harken back to traditional architectural functions. Covering Portland cement in brickwork or arranged timber was a common way of doing that. By exposing the underlying core of the building Brutalism was meant to display that transparency would only be allowed so far as to show what a monolith the power structure who used it actually was. Brutalist architecture has few glass openings, vertically massive internal atriums, large thick columns, interior or exterior walls rising at harsh unnatural angles, and consecutive terracing without bracing, all unachievable with traditional building methods or in then-contemporary Mid-Century Modernist architecture. All of this was only possible due to the strong central structure, representative of the aforementioned "monolith" of power.

Well it was deliberately created and sold by a specific architecture school. Not all brutalist is bad though.

There are a couple of brutalist buildings in Dublin that look totally out if place but also seem to fit in as part of the city now. I love them but I can see why other people might not.

Worth taking a look on street view at least

Modernism. Infatuation with the transformative power of high technology (both the physical and bureaucratic kind). The preceding bourgeois order was held responsible for class extortion (from the perspective of the emancipating proles) and synonymous with a small minded pettiness (from the perspective of a libertarian youth). Modernism was an iconoclastic project, a submission to an engineering fetish.

Probably Ernő Goldfinger is the most obvious person to blame, along with the smithsons, Basil Spence and Leslie Martin.

People think of brutalism as some weird 'means to an end' from the communist countries, but brutalism was an explict choice in the UK that the soviets copied.