I posted this in another thread and only just now realised that this thread is far more relevant. So...

I could be a sniper in PvP, I choose not to because I find it to be cheap and boring. I prefer a more involving game. I don't mind snipers in PvP so long as it's done in a realistic way - and it's not. Realism would mean that there would be one or two snipers in any one town, and once you took care of them they would be dead. In games with respawning functionality, it doesn't matter how many times you kill a sniper, they'll always be back. They're a bit overpowered in some of (not all of) the games that I've played.
As for PvE, I love sniping in games like Far Cry 3 where you have a large world to move around, much larger and more active-sniper-friendly than PvP games are. I think most of the camps I took over were done so from a very notable distance without ever being spotted.