Sniper has to exist because otherwise the game would just be everyone hovering around the middle of the map like flies around a garbage can.

Sniper forces you to go
>if I stand around in the open I will die
>if I have to constantly be moving toward someplace what's a good option?
and then as if by magic everyone is flowing toward the objective, since unless you're just fucking around (common enough but not that common) that's the smartest place to go.

Yes I know dying to hitscan man who can kill you anywhere on the map fucking sucks, but it sucks a lot less than this game turning into knucklehead DM fests.