Microsoft was one of the first major developers for the Mac when it came out originally.
Microsoft is happy for you to run Linux in the Azure cloud. Microsoft added Linux emulation to Windows. Microsoft gave up on Windows Phone (if only because Verizon and AT&T refused to approve new Windows Phones on their networks.)
A story that Microsoft honchos loved to tell was that some VIP dared to meet with Steve Ballmer and showed him something on his iPhone. I think the moral of the story is that Microsoft had changed at the time because Ballmer was insulted, but didn’t toss a chair at the guy.
The not invented here syndrome at that company is/was amazing. Microsoft wasn’t as bad as IBM, but they were on that path!