there are definitely too many bots in the games, either from leavers or because the lobbies keep counting down even when they are not full. i dont want to play with bots so i tend to leave when the game starts and i would greatly appreciate being able to leave without punishment if there are 3+ bots even in the middle of the game.
assuming there are no bots, leavers and afkers should absolutely be punished. if you have a Good reason to be afk in the middle of a game then you should have no qualms with waiting out the 15minute downtime you get afterwards. house on fire? dinner? guests? cat on fire? none of these or similar reasons should have you care about a 15min downtime.
you should not feel entitled to go afk to grab a snack and have your team suffer because of it. you have time between matches to do that, you can even STOP the queue and go on a bathroom break and join a game AFTERWARDS. if you see this as unreasonable, then you're an idiot. stop making random people carry your lazy ***.