I have tried Nexuiz/Xonotic in the past, but I was honestly not that
impressed. Maybe its because I played the original Quake 3 back in 1999 or so
and moved on. Nowadays, I would rather play something like CS: Global
Offensive or Team Fortress 2. Yeah, I know they are non-free games, but the
state of free games is on life support right now. It sucks, but its just the
way it is until there is someone or an organization to put forth the money
and effort to create an ecosystem where free engines can be used and the
authors can make money.
I also don't see what the big fuss is about since you are basically taking an
ancient game engine where the majority of work was done by ID Software 15+
years ago and aren't creating the engine from scratch. If you did all this
yourself and are releasing it under a free license, then that is pretty
awesome. You are basically piggy-backing on someone else's code and due to
the license, are making changes where you see fit.
What you need to do is re-evaluate what is important to you. If you want to
work with others, then do it and work as a team. If you want to throw a hissy
fit and fork it, then good luck to you. It gets tougher from here. If you
want to be original and create something that is beneficial, then do it. No
one is stopping you.
https://www.youtube-nocookie.com/embed/cc18WsYnlfc?rel=0&html5=1