MySQL's licensing has always been an "open core" mess. It's arguable that Oracle's more overtly commercial exploitation just makes this more explicit but MySQL was always dual GPL/commerical licensed.
I'm no fan of Oracle but under their stewardship MySQL has indeed started to grow up, with absolutely necessary improvements finally making it into the server. Too long has MySQL waved pathetic excuses for cryptic error messages, data corruption and downright stupid implementation. Sure, plenty of customers have found Oracle's pricing reason enough to leave and many have gone on to use other databases including Postgres - the open source db without any licensing issues.