The thing is, almost all hardware accessed through drivers has tons of bugs, at least it's nowhere near as close to "bug-free" as are things like CPUs or DRAMs which cannot hide their bugs behind drivers. The thing that one can hope to work reasonably is a piece of hardware plus an accompanying driver which knows to hide that hardware's issues.
So another way of putting what you said would be "on Linux there's no working driver for that piece of hardware, unlike on Windows where the 'proprietor' went to the trouble of supplying such a driver."
I didn't see him thinking that. Just that CPUs do not have as many bugs as other hardware - which I think is quite true. With CPUs a larger portion of bugs are found, and smaller bugs matter because they are not hidden by proprietary drivers.
FWIW, memory has plenty of bugs too. With respect to the original point, these are usually not visible to drivers (unless you count EDAC) because they're handled at the chipset level. However, for certain kinds of systems - especially embedded - that don't have chipsets these issues can become painfully visible. My own exposure to this was at SiCortex, where the memory logic was directly on the same single die as everything else that comprised a node.
So another way of putting what you said would be "on Linux there's no working driver for that piece of hardware, unlike on Windows where the 'proprietor' went to the trouble of supplying such a driver."