PUG = Join IRC, send msg to bot, wait till bot has enough players, start game
L4D = Create Lobby, wait till lobby has enough players, start game
I understand what you want to achieve but the act of making the PUG process more widely accessible removes the quality filter that makes PUG games work.
To achieve what you want I think we’d have to see a different approach to lobbies (maybe group only lobbies) or the Friend system. That way you have some quality control on the players. However the problem is always going to be that any control or barrier is likely to impact your playerbase. 
I’ve posted in the past about my belief that there should be a peer review system for players where you can vote up/down players and then using this data have the option of using it in matchmaking or server administration. Something like that would at least allow you to weight the match making to hopefully pick players with higher approval than those prone to rage quitting and griefing.