In a PvP game, some people are wolves and everyone else end up as sheep. Who is going to pay to be a sheep?
I can't really disagree with that argument. I rather doubt people will pay to be killed in PvP, with consequences like losing gear. But what if the idea was flipped?
If people won't pay to be sheep, will people pay to be wolves?
There are a lot of Free-2-Play games running around. What if one of the things for sale was the ability to attack and kill other characters? I.e. normally, players can't initiate attacks on other players. But if you subscribe, you can attack other players, and they can fight back. I'm talking full PvP with looting rights, a la original Ultima Online.
The thing is, in a F2P game, the players who don't pay primarily exist to entertain the the people who shell out money. To provide people to play with, to fill out dungeon groups, to create an economy that the subscriber can participate in.
It's merely a step further to suggest that, when it comes to PvP in an F2P game, the non-payers exist to be sheep for the subscriber wolves.
And hey, if you don't like being ganked, maybe you could pay more to be immune to PvP attacks.