Because it’s should be a group of people(small company maybe 5-10people ) who develop & maintain:
- fixing bugs
- developing new features
- testing on all platforms
- understand and develop UI & UX for…
- develop a usable editor(which is again a huge task)
For all that those people should be: programmers, designers, managers, artists etc… And all that requires a lot of resources. A hardware just to work on and again hardware on which test all the engine & games. From iPad’s & iPhone’s 5,6,7 to some android’s(list is too big, anyway at least needed 5 devices with different resolution).
And of course there should be a leader of all, which takes direction and coordinate next steps, contributing ideas…
All this just a very quick draft(really not full) of what I’m seeing how it should be, in real life its more complicated.
Just fork, well that can push someone and give some enthusiasm(like, ok I have it! now I will do how I want it to be), but it’s will gone after some time, very quickly. Because again, nobody will care about that fork… and many other problems will arrive.