For those who want more than five minutes but still want to finish a game quickly. This would drastically improve conversion rates for the site by enticing current RT players to become premium and put all the deadbeats out of business. Not to mention everybody plays on their phone or tablet anyway.
Yes horrible idea, all you have to do is outwait your opponent to fall asleep. I would rather see a 10-12 hour time limit. I think that is realistic for active players.