I think that most of the problems stem from a player's desire to be "better" and "cooler" than the other. They feel that they must degrade or flame the other for something, be it low level, their financial situation, their age, their grammar, basically anything, as long as it makes them feel better about themselves. I wouldn't necessarily call it 'hating' the noobs or 'hating' the little kids; it's just more of an action that some people do without even thinking to mentally compensate. In turn, this causes those being degraded to become angry, and then the real battle begins.