Paul Graham,
discussing how to deal with that ever-present pest the internet troll, makes an interesting remark:
Graffiti happens at the intersection of ambition and incompetence: people want to make their mark on the world, but have no other way to do it than literally making a mark on the world.
Which gets to the point quite nicely. Most often, assholes are just that because they have too much impetus and have spent too little time thinking about it. In a go-go-go world like ours this problem could likely worsen as the flood of information and technology bombards us. It's a stuck-in-a-box, don't-know-how-to-get-out situation. Consider a situation in which you don't have full knowledge of a question's domain, let alone the answer, but you are pressed for time. This is pretty much the essence of life, but some people handle it better than others.
It's an interesting perspective, and worth remembering the next time you find yourself in the situation: either as the asshole or on the other end.