There is a belief in OSS communities, that if a project is open-source, then someone will pick it up after it's abandoned by the original author/leader and that development will continue as if nothing happened. Just like for every project that has been handed to Apache Foundation
for that matter.
I don't believe it to be true, and I accept that if Jon decides to abandon Sublime Text then the editor is dead. That's it. Open source or not. Without a strong lead and designed by a committee ST2 would be nothing like it's now. W/o Jon ST's source code has little value!!
Once I accepted that, the difference between open and closed source development of core editor became meaningless (to me). There are people who will not touch a closed source software with a stick, and that's OK, I understand that.
But IMO releasing source code of ST changes nothing at all.