Otherwise you're building on an operating system which rebuilds a commercial upstream while explicitly refusing to follow that upstream's rules. IBM has lots of experienced lawyers, as I've heard.
It's also slower at releasing updates, including security updates.
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Sorry SSLy, I can't reply to you directly because I'm rate limited, it's very late here, and I'm not waiting for the rate limit to expire. So here's my reply:
I think previous decisions made by IBM have shown that they're fine at burning some community goodwill for short-term profit. People were called paranoid for worrying about the future of CentOS when it was taken up by Red Hat for "improved maintenance", and look where we are now.
Maybe you're right, but I personally wouldn't want to build anything serious on top of that "maybe". If something happens, lateral migration should theoretically work, of course..