DQ uses 1's, 2's, 3's, 4's and 5's.
4's don't function without 1's.
2's can work with 3's, but the other combinations, 2 2 and 1, or 2 and three 1's, go away without sufficient 1's.
3's go with 2's, but otherwise need two 1's.
Sectioning off more and more of the playerbase screws with queue times, especially when paired with role selection from new champion select.
If 1's in DQ get sufficiently low, DQ's kinda screwed. If indeed DQers are super common like is being asserted, then a decent dip in 1's would quickly be a problem
SQ would function off a lower population due to fewer complications, but could still run into problems if not enough people went.
There could be additional issues though, such as certain roles being more common in SQ or DQ populations.
And as with before, these problems would all be most common at the top of the ladder. May well be that both SQ/DQ would blow up and fail for the top end. Could also conceivably be that both would co-exist perfectly fine at the bottom of the ladder.
Not that I'm particularly happy about being a sacrifice to DQ. I buy that they can make it "fair", but it's still less fun having some segment of each team randomly work together way better or way worse than what I'm used to, and just happen to have other skillsets that offset it in the appropriate direction.
Or the people who feel more comfortable popping off their mouths because they have a friend to back them up.
Basically I'm having less fun.