Someone got banned for pvp on a pvp server on retail? Sure thing Pinocchio. ;) Maybe, just maybe, he got banned for camping quest givers, which could be considered harrasment, but he was not banned for ganking lowbies.
Maybe you should try ganking for a while and maybe after that you can see how ganking can be enjoyable. There is a sport in ganking, I'm guessing you're not familiar with it yet.
Ganking sport goes like this:
1. Queue for Random BG
2. Start running around ganking people
3. Count your ganks
4. See if you killed more than your friend after BG finally pops.
5. Winner gets Berserker buff, if possible.
And yes, there is a reward, there is lots of rewards, different rewards for different people tho. Some might get a good laugh from lowbies trying to escape. Some might enjoy killing alts and then killing their mains as well. Some might even be role-playing as a terror of stranglethorn, who knows. I like getting free honor from people leveling in northrend. Also, reading this thread has been a lot of fun, that's a reward from ganking too. I would guess that you've enjoyed this thread as well. Doesn't that make it a good thing that the OP was ganked. I mean, too bad for OP, but lots of entertainment for many others.
Why to gank? Personally I gank when:
1. I dislike them for some reason
2. I dislike their guild for some reason
3. I hate their name
4. I save someone from being killed
5. Revenge (edit: not a revenge as in I was ganked when I leveled now I gank some randoms who had nothing to do with it. More like "this person corpse camped me so now I'm gonna gank him back."
6. Bored
I totally understand ganking. However corpse camping for no reason and camping quest givers I don't really understand. And btw, everybody has irl problems, but not everybody ganks, linking those together doesn't really work.