Not sure if you were referring to the specific news in this post or in general - but for people who aren't aware he did write his own game with it's own system Phoenix Dawn Command
Right here is the problem.
Eberron has a lot of fans. And a lot of people like Keith Baker.
Yet when he developed his own game, it ... well, how many people heard of it
? And of those people, how many played it
? Honestly, I bet that Phoenix Command (the 1986 RPG) has a much higher name recognition in the community as a whole simply because it's kind of a punchline.
What worries me about this is that we have a lot of people yelling to burn it all down. Well, cool. I think that there is this unstated belief that if we just burn it (D&D) all down, then somehow everyone will start playing all these other games. But ... where is the evidence of that?
TTRPGs has always been a discretionary hobby. Maybe people are happy with it going back to being a much smaller hobby. Maybe this 5e period will be looked back upon like the 1979-84 period. I don't know.
Who knows. Maybe there is a large market out there that just can't wait to play PF2e, and the FiTD games, and all the indie games and one pagers that our hobby has ... and they've just been waiting, pining, for the Death Star of D&D to get destroyed by the Rebellion in order to play! Or maybe not.
If I was Baker, I would release a rules-agnostic setting, or a generic (but D&D compatible) setting that he has control over. But I'm not.