That last bit's actually a known phenomena in the field of sociology (and probably psych, too), though I forget exactly what it's called. Or if it has a particular name or something... probably, but eh. But yeah, folks tend to single-dimensionalize, if you will, people that aren't them or theirs. Naturally, if it happens to them or people they're close to, the tune changes and it's a complicated situation and there's lots of reasons for X or Y to happen and etc., so forth, so on. It just seems like it's rather difficult for a lot of people to make the connection that there's that sort of complicated situation for... well, pretty much everyone.
It's a tendency that's possible to break, but it takes training of some sort for most people. S'one of the reasons teaching psych/sociology (and quite possibly the mechanical aspects of philosophy -- rhetoric, logic, analysis) to folks is generally a pretty good idea, though the general youth of the former fields makes anything systematic still difficult to implement.
On the personal level, something in me's broke and I've never really been capable of feeling anything positive from that sort of spite. Other folks seem to get some kind of charge from certain negative emotions or demonizing other people and I just... don't. Haven't been able to. Don't exactly miss the capability but it makes comprehension hard at times