To be fair, MySQL was not really ever run as a community project. It has always been a vendor proprietary database with an open source license. Sun paid a very large sum of money for it to continue to collect commercial license and support fees, and that is why Oracle maintains it today.
If anyone actually manages to use it without paying Oracle for licensing and support services, that serves no real purpose to them other than as a loss leader for future paying customers. If they allow unpaid customers to get timely updates and report bugs _at all_, those are much better terms than they offer with any of their conventional products.
There is a lesson to be learned here. Commercial vendors are naturally in the business to turn a profit. If the best way they see fit to do that is to make periodic open source code dumps of a internally developed code base, or supervise a community project where they hold all the cards, vendor lock-in is nearly as likely as with any other vendor proprietary product.
Freedom to fork is nice, but forking and maintaining something as complex as a relational database server certainly isn't a proposition to be undertaken lightly, even more so when the trademark of the original is hardcoded into the ABI. If you use MySQL you are married to its future as a commercial product. Divorce is not the most practical option.