"People living together often butt heads" isn't even an out-there concept. (It's one reason I and others would argue that even communes should have individual living quarters—everyone having their own apartment in a shared building versus everyone having one room in a sprawling mansion. The former can have shared common areas, but the latter becomes one giant common area.)

And I'll throw another data point in the pile: I've had too many friendships soured by turning friends into roommates. In part because we were all immature and bad at handling conflict, myself included (ah, college!), and in part because there can be people in your life who you love and cherish but do not want to share a kitchen with. I'd imagine tensions would have been higher if only one of us was paying rent and the others were living there for free.

You heavily implied it by discussing a negative experience, its consequences, and speculating that the communal aspect was the root cause. I am a little bit surprised that you are denying that core point.