With all due respect, you can't be a "a sniper" all the time. If you support your team by sniping to give them cover so they can advance, then fair enough, but there are too many guys already in this game setting up camp trying to get some random kills undoubtedly to show off how awesome their stats are. Play a few different classes depending on the situation. If there's a tank coming change to Engineer and take it out with your RPGs or if you're brave and want to have fun take it out with some C4 (great feeling). If there's an alleyway where everybody is stuck pick up an LMG and provide suppresive fire.
I like playing assault these days and sticking right behind some better players and backing them up and reviving them as soon as they go down while also trying to take down some enemies with some of my new gun toys. Quite satisfying and it helps to win the game I'm sure.