I think both sentences are ugly, but I think that's because "breaking functionality" offsets the simpler words in the idea. "They fuck up their shit just because they can", however, is smoother and faster than either of them. Swears have a certain poetry to them in writing, kind of like how oohs and aahs work in music. (This is my own opinion, mind you.) On their own they convey nothing, but placed neatly into a sentence they help the whole message flow.
So I think I'm agreeing with you here.