I don't use these tactics in FPS games, but I really don't mind people camping. Generally campers know of places people go most often so they can get kills, and they may find that fun. For me, it adds a new level of challenge because I've got to be prepared for the campers, which is why I never go around a corner without strafing and checking all the little corners and hiding places.
Generally, people who say they don't like things in games is because they are always owned by them. It's like people who say the Pyro was heavily unbalanced when it had 50+ health from the backburner, yet when I played I still had more trouble with sentries and enemy Heavies than Pyros.
Instead of complaining about campers and anything else you're not good at solving in a game, try learning how to solve the problem and kill the campers using something like a grenade round the corner or making sure you check areas are clear or something.
Generally, people who say they don't like things in games is because they are always owned by them. It's like people who say the Pyro was heavily unbalanced when it had 50+ health from the backburner, yet when I played I still had more trouble with sentries and enemy Heavies than Pyros.
Instead of complaining about campers and anything else you're not good at solving in a game, try learning how to solve the problem and kill the campers using something like a grenade round the corner or making sure you check areas are clear or something.