When people actually aim down the scope and snipe as sniper rifles are supposed to be used, there's no problem really. It irritates me though when I'm running (or walking) around and suddenly a sniper pulls up from a dead sprint and OHK's me. It's frustrating but it's not impossible to counter. If they miss the first shot they're usually done.
Another issue is the way people use semi auto snipers. I don't understand the point of putting in the SVU without a significant amount of recoil. Even the XPR (I think) has more recoil, and isn't spammed so much. But when you hear 5 sniper shots go off in 2-3 seconds, it's not even being used as a sniper rifle. That kind of weapon is just a crutch for people that can't snipe properly, and it doesn't teach them how to snipe either. If they won't take out semi auto snipers and just leave bolt action ones then at least put more weapons like the XPR that can be used without spraying.
Trickshotting can be humorous at times but when you're playing search and the last player on your team loses the game because he tries to jump off a ladder or building or something for the last kill instead of trying to win then it's irritating. Or when an enemy runs past a sniper on your team and you end up getting shot in the back because the sniper might be trying to quickscope or something (or maybe they just keep missing lol). Doesn't happen too often though, but it can mess up the flow of a match
My DSR-50 has a 2.48K/D with 600+ kills. As for the objective part, this can change from game to game depending on how close I can get to the objective without dying. If I can get into the objective or keep enemies from getting to the objective then I am being a objective sniper.
25 and 3 is a 8+ kdr, so 2.48 is a fair way off, and hiding out on the peripheral picking off objective players doesn't really count as playing the objective, but whatever.