Well, if you wrote the code, you own the copyright. You can release it under any license you wish. If other people wrote the code, then they've expressed their

Well, if you wrote the code, you own the copyright. You can release it under any license you wish. If other people wrote the code, then they've expressed their wishes through the terms of the GPL (which haven't really changed in the last decade), and those wishes include forbidding additional licensing agreements from being put on top of the GPL (which appears to be the objection in this case).