I think that if the opposing team does not ban a champion that it should be given to your team and your team gets 4 bans instead of wasting the ban

Nah, it's cool the way it is.

If they don't ban, they don't ban. You have the option to ban, not the requirement to.

I'm not sure what you're hoping to achieve Dconn. As it stands it's "wasted" if it was given to the opposing team it would be a down right penalty for not banning. Consider however the unrealistic scenario of two teams who have the exact same 16 champions available on every player.

In this admittedly contrived scenario a team might skip a ban to try and ensure access to options.

I just hate when my 'team captain' is afk and we get no bans ):

Sometimes wasting that ban is a strategy, so it is not wasted. This forces the other team to ban a champion that the team may want to leave open, thus taking one of your necessary bans away from you. It's not used that much since people have more than one strong champion, but it can solidify your pick if the bans work in your favor.

-RyuTres