That's also another awful idea in a MOBA - again, that works for other games but there's a reason why you don't see it here, in LoL, or other examples.
By doing that they would:
a) mitigate the consequences of allies leaving therefore implying that leaving is not as bad
b) Increase player frustration of joining a match in progress on a losing side, or on a winning side where the game is like 1 minute from being over
c) Decrease team synergy if people picking end up picking bad or trolling themselves.
All of this to avoid a simple solution - if you aren't gonna be there to pick a god, you shouldn't be in the queue.