@yogthos 70-90% of WEB SERVERS run linux. so many corporate servers run windows but are behind intranets.
I bought a few HPE servers new, and guess what: they all had a windows boot manager entry.
It's also that linux is the choice of load balancer, even at MSFT: netcraft shows microsoft.com as running linux. They may in fact be running windows, or maybe freebsd (e.g. 4chan/HN).
Disclaimer: I work at microsoft but not windows or azure.