Brutalism is an architectural term, not really one that people associate with EDC, but it refers to minimalist work with exposed architectural elements and a general lack of facades. Build something out of cinderblocks and ferroconcrete and steel, you've probably built a brutalist edifice.
Applying the concept to keychain tools, that's what I like. If you ask me to pick between a nice multitool and a brutalist piece of steel that's been milled to work as a prybar, a hex wrench, a screwdriver, a bottle opener, and a carabiner clip, the latter is going to catch my interest. It'd have to be one hell of a multitool, like something Q would make for Bond, before you're even talking about making it a hard decision. For a guy with hands my size, trying to use a miniature Leatherman is kinda like watching a gorilla ride a tricycle anyway.