Having played through Vanilla, where World PvP was all the PvP I got.. I can tell you that, for me, the guards weren't part of it. Neither were the at-level players. Back then, the only reason we attacked cities was simple: It brought the 60's out.

I realize the reasoning and general mindset of players has changed and, because of that this really has no basis in answering your quandary, but at the time we would attack a city to get some attention, then back up and wait for the 60's to pour in. It was loads of fun and done in a fairly respectable manner.

I guess the guards still don't make sense, but what I'm saying is the only ganking lowbie towns I respect is doing it for the purpose of getting the attention of capped players to fight, and leaving the town itself alone while you do it. I don't kill quest givers, or innkeepers, or flight masters, because that's just dickish.