The vast majority of players are carebears. Always been that way. That's why you have to keep that in mind when designing any MMO. If you don't, they aren't going to stay and pay. If there were enough PVP players to support a game, then there would be MMOs that succeeded that way. EVE is the only one in 30 years. I enjoyed the hell out of Warhammer Online, but even that died after a few years.
It is just another issue that leads back to why people play games. Everyone wants to be the hero. No one wants to be the zero. The biggest reason why instancing is needed is rooted in just that. Everyone who pays a sub deserves to be able to play every part of the game. You can't do that with camps being a thing in an open world game. You can blend things a bit, let everyone who hits a mob get loot and kill credit.