Why are high pingers allowed?

Why?

They ruin the game for everyone. They are always at the top of the leaderboard. It's not because they are good, they are obviously exploiting high ping, getting a big advantage from it. You can't shoot at them, as it's like they are playing in the future, and keep teleporting. 

So why? It would be good to understand the reason, because if it is to get more players, it's having the opposite effect.