ok i slate QS's all day everyday but a proper hard scoping sniper as a defensive assest in objective modes is worth its weight in gold to a team. yes that involves camping but i don't care, i call that tactics.
its a game mode/play style issue.
if someone is a cheap ass QSer who cares not about helping the team and costs you caps and defends by being a douche bag its because they are a douche bag
(if your on my team and QSing but defending/capping i may accidently not notice lol)
i often overwatch a flag with an LMG keeping the other team off it until i'm dropped. that is camping in this game but its tactics in any other, the focus is the objective... dig in and defend or move out and assault. the bulk of a team should be offensive but some should be defensive.