The more easily people can feel free to ditch Windows, the better.
And I don't mean that as a slight against Windows. I mean that there should be better competition in order to spur more comparisons and improvements. Even people who love Windows would benefit from better rivalry. The way it has made Microsoft want to improve gaming under Windows is a perfect example of why. They could be doing much better on many fronts, and likely there are ways Linux might improve as well.
Additionally, if it is easier to move more freely between operating systems, that makes it easier for people to choose what is best for them. Feeling stuck making do with something subpar is not good. Everyone can agree to that.
Everyone should want Linux to get better. And Windows. And all other OSes.