I don't know about the JVM, but what you mention about MySQL has to do not strictly with the GPL but with it being dual licensed (GPL and propietary) and as a result many Linux distributions like Red Hat, OpenSUSE, Fedora and Arch decided to make MariaDB -which is only GPL, compatible with MySQL and has more features- the default and it's readily available in most -if not all- distros, Windows and Mac OS X. So I would take the part of "competitors always a step behind you" with a very big grain of salt.
