I agree to some extent. The problem is that most, or a lot of players, actually do enjoy world PVP. So if you want to be playing with top guilds/top PVPers, you kind of HAVE to roll on a PVP server, no matter if you ultimate goal is PVE.
But even if you still enjoy PVP, that doesn't make you any less sad or pathetic if you corpse camp a level 1 dude for 2 hours as a level 60 dude. Which is my point all together :P.
Sure, it's not in any rules set out by Blizzard. But most players still find it to be grief or in poor taste. Just a matter of morality!