Microsoft and Windows were never the enemy.

To quote Linus Torvalds from 1997: "I don't try to be a threat to Microsoft, mainly because I don't really see MS as competition. Especially not Windows - the goals of Linux and Windows are simply so different."

He got less humble later on when momentum started building behind Linux. To quote Linus Torvalds from 2003: “Really, I'm not out to destroy Microsoft. That will just be a completely unintentional side effect.”