Linux is not the next Windows, and will never be the next Windows. It's been the year of the Linux desktop for twenty years, and it's not been achieved yet. It's very good for the server environment, but it was the next Unix, not the next Windows.

You're wrong, but not in the way that you think.

The concept of a desktop operating system is dying.

Different distros of Linux are very capable desktop operating systems, they are fully featured and competitive with Windows in pretty much every facet. They may not be the next Windows but that doesn't matter. 95% of the use case for an OS now days is the ability to run a modern web browser.

Regardless, you shouldn't dismiss something just because it doesn't have mass adoption. Mass adoption doesn't necessarily reflect the amount of engineering and quality of the platform.

The whole Windows vs Linux debate is pretty much obsolete and becoming less relevant every day.

Linux is already running on more personal computers than Windows. We call them tablets, phones, and think of Android as it's own OS but the reality is it all came from just one guy at the beginning.

If you define "the next Windows" as the operating system that supersedes Windows, then Android (based on the Linux kernel) arguably fits the bill.

But Linux being the next windows or not, the point here is that one guy's hobby project can change the world, so dismissing something because it's just one guy is dangerous. I have seen many cases where one passionate developer has produced something a large corporate team would be proud of.