Snipers can be very effective at times. It depends on what area of the map the current battle is taking place in. Snipers can lack in their effectiveness if a player remains a sniper
at times when they aren't very appropriate. What I'm trying to emphasise is the need to
switch classes.
Theyre annoying because they dont contribute anything to the team.
This is simply not true. At the
right moments they can be very effective at doing things other classes may struggle to do.
A primary example is Dustbowl stage one. Red snipers can be very effective in the first area at slowing down Blue's assault, especially by picking off medics. The long, clear line of sight means you can have a field day and do some major damage in holding off the initial assault period. However, once the first CP is taken by blue, being a sniper is far less effective in the second part of the map. At this point, a switch to say, Demoman would probably be a sensible approach.
What tends to annoy me is the mindset of players thinking "I'm a sniper", or any other class for that matter, in the sense that they feel completely devoted to that class for the rest of game, forcing themselves to try and play that class when there isnt much hope of success. You're a
player and there is no need to pick "your" class and stick to it. You have the ability to switch to a different class should the need arise.
I'm essentially regurgitating a common argument in TF2 and that's that each class is useful in different circumstances. To brandish Snipers as a class which "contributes nothing" suggests to me that you need to play the game a little more. Even on 2Fort, it may seem like Snipers are "ineffective" but you need to counter their Snipers with other Snipers, or else their Snipers are free to pick off your team with little resistance.