ARAM - 15 is too long

So here's the deal. ARAM games are a lot of fun. Playing random champions in a line setting can be a load of fast action, bursts of damage, and the always enjoyable 5v5. The problem is this, these games tend to last about 20 minutes, the longest I've ever played was 28:55, and based on the champion selections some games are decided right out of the gate, like say if you all get spawned with melee champions, or all AP champs. It isn't worth getting slammed with a leaver ban just because your team can't win, so why don't we just accept that the surrender timer be reduced to 10 minutes, or even 5 minutes as some players have suggested?