1. Control and privacy. The server does exactly what I choose, not somebody’s business model.
2. Once you have other users, it’s not a hobby anymore. People are not amused by downtime.
3. The w3schools.com tutorials have been good for me.

Usually. You already know the answer to that…

Linux might not do everything you want it to, at least not easily, but it usually doesn’t do things you didn’t ask for, unlike all proprietary OSs these days.