Sorry, but I have to reply from my phone, so can't write that much.
You don't play, but you are suggesting penalties and forcing people. The 360 had mics for Halo. Did most people use them? Not for random matchmaking.
You think forcing and threatening people would encourage them to play? They would just not play because there would be a penalty if something happened to them.
People are already forced to go to a website to get a group. So the solution is forcing them to stay?
Mics only? That works only if people talk. They don't. That is what your don't get. Mics are the only communication method and it does not work already with randoms.
This is not RL. This is not Dota 2. Forcing people with penalties does not work, which is why I keep bringing the Dota 2 thing: People still leave games even with threats of temporary bans. It's not like they can't just play something else, can they?
So, i've provided means to address the major concerns: Quitters (which works by punishing the first quitter), communication, and have it be optional.
Now, mind you, the issues that exist in an optional MM already exist in the game. The game already has quitters, the experience can be compromised by mic-less players, and there are zero in-game MM options at all for raids
so, everything i present is a step in addressing these issues. Do people still quit dota2? sure, yeah, and if that behavior continues they get sent down to quitters hell until they become better players. Now, has that affected their community in a negative fashion? do they have less players than before? And are the most hardcore dota2 players opposed to the current quitters penalty?
I think it's fair to say that you could answer the questions I have posed with a "no" and you'd be right.
So my suggestions seem to help remedy not only issues regarding the implementation of an optional MM system but can even carry over to the rest of the game, if bungie so chose to do so.
Now, if you want to argue that an LFG-like system being integrated into the game would be helpful I'd agree. Anything that keeps the player in the game is fine by me. But that, too, would be a form of MM.
So, what do you suggest that could be done to bring about a good optional MM system, one that address all the concerns the people opposed to MM have?