I think the notion largely boils down to another dogmatic display of tech industry's megalomania.
A physical computer is still a computer, no matter what it's computing. The only use a computer has to us is to compute things relative to physical reality, so a physical computer seems even closer to a "real computer" or "real computation" to me than our sad little hot rocks, which can barely simulate anything real to any degree of accuracy, when compared to reality.
It's sort of like a car mechanic telling you "SQL query, eh? It must be similar to what happens in an intake manifold." For all I know, there might be Turing-equivalency between databases and the inner workings of internal combustion engines, but you wouldn't consider that to be a useful take.