Nice analysis. Sigmund Freud would be proud of you.
However, some people gank lowbies because they are...You know, bored? Doesn't mean they suck or they still carry the burden of "bad touch" from their childhood.
Actually, some people do it so that threads like this start popping up. It makes it even more amusing.
And as one of the imps mentioned, why shouldn't you weaken the opposing faction? Slow their progress?