So if everyone believed in the invisible dragon under your bed, would that shift the burden of proof to you? I don't see what the general consensus has to do with anything.
The people who say quantum mechanics exists don't just claim it, they can demonstrate it through peer reviewed evidence. Quantum mechanics is also a theory based on observable facts intended to propose testable mechanisms by which those facts can be explained. My claim of a dragon under your bed has no such backing.
As smarter people than me have said, that which is asserted without evidence can be dismissed without evidence.