Oh boi, did someone actually read my post? His main argument is that there are not enough players and that this problem is not a bug, which is just plain wrong. Maybe on anz server the player base is small but not on eu.
I made several smurf accounts starting from bronze 5 and i got games in less than 100 sec. But once my hidden mmr differs too much from my rank i cant find a game anymore. And this doesnt mean 1000 sec waiting time, it means never.
Yes of course the reason is that the system tries to match you with people in bronze with a mmr of >2500 or even more (depending on your winning streak) and obviously wont find any because thats not how the system is intended to work. But its not because of too few players its because of this garbage distinction between hidden mmr and rank.
So as the blue guy said its mostly affecting smurfs (not directly but thats what he meant with people who leave games) who leave in draft to keep their rank low but its also affecting some regular players.