ok hear me out. would you rather:
A. wait 5 minutes for a queue and be forced to play a role you don't main and probably lose
B. wait 10 minutes for a queue and play your main role, giving you an actual fair chance of winning
maybe autofill isn't that bad in norm games, especially since most people that play norms just want a quick 25 minute game, but when it comes to ranked, people don't care about how much time they have. if they get their main role, they're happy.