As things are currently it is possible for anti-social, selfish players to deliberately ban a champ that they know their own team member wants to play.
This happens too frequently in low elo, where there is a greater concentration of immature and ignorant players.
There is no reason that the game should allow this anti social behaviour.
A simple fix would be that it is impossible to ban a champ that another player on your team has highlighted as the champ they are going to pick.
In the same way that the game doesn't allow you to ban a champ that has already been banned.
This might not sound like much of an improvement to those who play in higher elo, however it will make a big positive difference to many people who have their enjoyment ruined. It will also prevent accidental bans of champs that your teammates want to play, when you are in a rush and don't notice what other people on your team are going to pick.