Mostly an expression of anger and frustration.
Lots of people *think* they're going to change others' minds, show them what real justice looks like, teach them to be more accepting, and so forth. The intentions are noble. When others don't respond the way they want, though, that's when it devolves. Too many people reach the point of "other person not persuaded," and instead of taking a right into "get on with my day," they take a left into "how DARE he not be persuaded! I'm not done until he admits I'm right! Load the flamethrowers!!1!omg!!" It's an entirely understandable instinctive response: if you don't leave a gorilla's territory when it snorts and postures at you, its next action is to beat you down. On the Internet, we can't throw literal fists or rocks, so the beat-them-to-a-pulp instinct has to be satisfied with words. I've watched a few threads devolve into /quote/quote/quote/quote/quote ragestorms perpetrated by fools where between all the participants combined there might have been 10% knowledge of the rules of debate. This incomplete knowledge itself becomes a point on which to argue, with accusations -- some justified, some not -- of straw man and ad hominem usually taking top positions.
I've only gotten really upset with a couple people here. I remember some guy claimed that bar patrons deserve to drink piss -- literal piss, he was bragging about sabotaging beers at the bar where he worked -- because he didn't like the laws regarding hourly wages for tipped employees. It's pretty obvious there's no correlation but, in his impotence, hanging on to rage and making someone -- anyone -- pay for his unhappiness was more important than, say, doing anything intelligent.
