@exselsior the OP is indeed trying to host themselves already, I've seen their lobbies in the list.
Maybe the thread is partly about that solution not being entirely frustration free, and that might have something to do with people's reluctance to join lobbies hosted by lower rated players, but I'm just guessing.
Personally, I have to admit whatever gut feelings I might have about a hypothetical gap only queue are worthless since the death of 4v4 tmm came as quite a surprise to me. It was vindicating, but surprising as hell, based on what I perceived the consensus to be at my rating level at the time. The fact that it even existed at all is proof that fullshare was at the very least controversial, forcing the devs to launch tmm with both, which was the right call.
I wonder if no-share's utter failure came as a surprise to any them as well, and if so, maybe it's worth reminding ourselves our intuition is not perfect at predicting how large, mostly silent communities will react and can't replace actual experiments.
On the other hand, if it came as no surprise at all to anyone on the dev team, more the reason to trust their judgement on this, but it's interesting to think that they were willing to entertain no-share then just to prove to people hardly anyone wants to play it, so it must not have been that huge of an effort.