It's not an emergency at Microsoft for two reasons:

1. Microsoft doesn't make their money from Windows anymore. They make their money from services, like Azure and whatever they are calling their web-based Office this week. Windows is now mostly a telemetry-collection system for them, not a product.

2. People who hate Windows don't have a choice. Regular people are issued a PC and its OS from their employer, and can't change it. Consumers who buy low-end laptops for school or hobbies aren't going to pay twice as much for a Mac. And outside of HN, a vanishingly small number of people are even aware of Linux or other FOSS alternatives, much less have the ability to install and use it.