I proposed that a company would obtain the GPL source code for MySQL, compile it, and then SELL the resulting binaries. That clearly is illegal, both a violation of the GPL and MySQL's trademarks.
No it's not. As long as the package they sell also contains the source and all files needed to build the application, they are still adhering to the GPL.
GPL doesn't preclude selling binaries. It just mandates that the user be able to easily obtain the source from the distributer.