Microsoft is so far behind in cloud/virtualization that they'll have to start paying people to use 365.
What's the old saying...
"Fool me once, shame on you, fool me twice shame on me"
The "cloud" has very rapidly evolved and Open Source is a gigantic force there.
Look at AWS EC2 and just check how many AMI's are linux based...
My search shows of ALL AMI's on EC2
-- only 820 are Windows
-- 5,762 are Linux (ubuntu, debian, redhat, centos etc)
Since AWS is by far the largest IaaS Public Cloud ... what does that tell you about what's being adopted in "cloud"