However, you're right to say that consensus doesn't govern, supermajority does. Who represents the supermajority opinion in the transaction scaling debate? It's not the BIP101/XT contingent, is it? Are you really going to try to pretend that even 51% of Bitcoiners support your views? You're in the fringe, and will remain there.
I think it's even stricter than that. If dev and mining majorities both have a supermajority against something, it's definitely not going to happen whatever the rest of the Bitcoin space thinks about it.
Agreeing against something is considerably easier than agreeing to a concrete proposal.