Ten bans would only improve the overall league experience

The only result of ten bans would be overall positive.Ten bans would add more variance to gameplay as it would allow less viable picks in the current meta to be picked(as a result of premium picks being consistently banned).Champion diversity would increase as a net result.The overall power levels in league would also decrease as less premium picks would be available,and would improve gameplay inherently as champion strategy would not necessarily rotate direct meta calls.

Really the only reason why Riot wouldnt want ten bans is if they dont believe in player competency to regulate their ability to balance.