Every person I personally know in the industry works less than 50 hour weeks. And often they go home and work on their own projects at home, in effect working a lot more.

Working on a hobby isn't the same as paid work. We don't sit here and say that folks going home and playing games are working. It is the same with side projects of any sort. These are hobbies. That they happen to line up with something you do for paid work is just coincidence. This is true even if you make money off of it from time to time.

Hobbies aren't work.

(Hobbies that have become your day job or are a significant portion of income are no longer hobbies)