As a top lane, why should bot lane be able to decide the game for me?
Sure, I may tp down there, but that doesn't do it all. I'd have to wait another 3 minutes for tp to come back up.
You may say "leave lane and go to their lane". I mean sure that's possible, but in my current elo, if I leave my lane, the enemy top laner proceeds to stay in top and get towers, and it takes awhile for my team to notice (happened many times).
Bot lane feeds and then I lose game. I end up being the only one able to kill the fed person because I stack good on nasus.