My observation of the whole SBMM saga is that Bungie heard complaints of teammates who played with their feet which frustrated the better players that had to do major carrying, so now you're much less likely to play with feeties but in turn makes every round more like sweaties due to the higher skilled opponents.
Damned if you do, damned if you don't. Am I off the mark?
I don't remember a lot of griping that lead to SBMM. They just implemented it for funsies apparently. And it sucks.
There was virtually no complaints about the matchmaking system prior to December, except maybe for some regarding the changes to Trials from Y1 to Y2.
In December Bungie changed the formula. We still don't know why. Players noticed and asked. Bungie denied. Players grew more and more certain, Bungie said it definitely didn't change. Players still pushed even further on this issue, and it turns out, yeah it did change. Literally every playlist was updated over December.
Players aren't happy. "Why fix what wasn't broken." Bungie says it's for the best.
Players cry, really fucking loud. Loud enough it got the attention of several websites and journalists. Journalists wrote article, Bungie finally admits change may have been bad.
Bungie doesn't revert change. Instead, tampers with current formula in effort to reduce laggy games. Something that was a factor in the unhappiness, but not actually the core issue. Players were sedated for a time, due to Bungie actually talking to us.
Time goes on, and players don't feel like they really got what they wanted. Bungie's changes seem to be what they said they would be, but the game still doesn't feel as fun as it was before the first December change.
Players are left scratching their head wondering why such a drastic change was made, when the game seemed just fine before.