I don't think MS is particularly criticising Linux in raising these bugs. It's the kind if thing they should be looking for, given that MS are promoting Linux running on Windows in the form of WSL. Though I suspect that MS's public relations department enjoys making a song and dance over what is, actually, a fairly minor and run-of-the-mill bug. It's already been fixed upstream - most systems will be patched in a couple of days. I don't expect a campaign of Linux ransomeware.

It only affects desktop systems, which are about 2% of users. It doesn't affect servers, of which most are Linux. Compared with the recent log4j bug - which is still not universally patched - or the Spectre vulnerabilities, which were baked-into years of Intel processors - this is trivial.