Well the people who don't give any fucks want to make their life easier so they do a minimally competent job and are usually supremely skilled avoiding pain. The disconnected people don't actually do any work at all. The incompetents cruise in, full of ego, poop everywhere and expect everyone else to clean it up and take responsibility for it. I don't mind that job because it's an open ended task. As for it being their fault, no it's not really, you're right. But management need butts on seats apparently so standards will be reduced until they are full.

Also many incompetent people, when faced with enough pain, will turn into competent people and eventually stop giving a fuck too.