I wasn't suggesting it's the exact same scenario, but it definitely seems a little disingenuous to create a fork of something that you chose to sell, and complain (https://web.archive.org/web/20201003111459/https://www2.comp...) about it becoming "open core", only to then make everything you do a paid product with the one exception.

That's before we get into his claims about maintaining drop-in compatibility "as long as MySQL has a larger user base than MariaDB".