Fuck AI

No, they don't. You're acting like all those benefits you listed are payment or compensation for the work they did. If those serve as compensation, they don't create a forward obligation. The paycheck you get at work doesn't entitle your employer to your continued labor.
The community isn't owed shit for the guy giving them something useful that may have looked good on his resume. It's entitled as fuck to think you're owed something because someone built something you found valuable enough that someone else wanted to hire them.

To answer your questions:

• because it's their project and they thought it was the right tool for the job. What answer were you expecting?
• because the community isn't working on the project.
• probably not.

Seriously. Demanding someone give up control of their personal project because it's too important for them to run as they see fit, but not important enough to support or help maintain.
Fork it and maintain it yourself. Literally nothing is stopping you. You're just as equipped as he is, other than not being the inventor of the underlying technology.