[rcxdude]

There are some objections/worries on the grounds of 'is reality fundamentally quantum or is there some other model that is classical and means QC doesn't work'. But it's also worth distinguishing the different approaches that are being used. Other QC computers are doing actual calculations, just not ones that demonstrably beat classical computers for practical applications, and if the whole concept works then there is a threshold where quantum error correction can take the whole thing from 'doesn't scale anything but the most trivial examples' to 'relevant for cryptography' in a relatively short time period.

Microsoft's approach, however, is a bit of a maverick one even within QC: what's in contention here is whether they've even made a single qubit, something other quantum computers have demonstrated conclusively (the difficult part being doing operations on those qubits with low enough noise to be able to achieve error correction).