Why can't we get bans in All Random Game modes?

With the latest rotating game mode, I just can't bear myself to play it anymore. It's not because the game is basically normal SR but with randomized champ select (actually it is one of the big reasons I really don't like playing it) but it's the fact that I can't ban out certain champions in the selection screen. Why is it that we can have a ban in most modes but when it comes to the all random we don't get any. I just want a small ban phase to take out some of the more annoying champs that people may get. I don't want to have to deal with facing because the enemy got extremely lucky with their picks and have the feeling that I couldn't do anything about it, not even banning at least one of those champs.