It's not surprising: The GPL mostly torpedoes commercial uses, and EA does not want to give their competitors code they can use in their own proprietary games.
It does effectively prohibit you from competing with someone else who compiles there code and puts up a download link for free. The “but you can still charge money for it” aspect has always fallen flat, especially since most people won’t pay for disks containing something they could download online these days.
You could presumably make a derivative game using the engine, and sell the game's assets, while complying with the licensing terms on the engine code.
I don't know any examples of this happening, but we've seen the engine/assets distinction before when DOOM and Quake were opened. Their source code was released as Free and Open Source software, but the game assets remain payware to this day.
Yeah but if I use this GPL licensed code as the basis of a new game, I have to release the source code for my new game as well.
The vast majority of game studios aren't willing to do this, so effectively releasing it under the GPL means that it's much less likely that a competitor uses the code.
Asset flips from other countries with more permissive (or just hard to access for foreigners) legal systems are already a problem for game developers--releasing the source code for your game would ensure that you'd be inundated with assets flips almost immediately if your game is any good.
https://www.gnu.org/licenses/gpl-faq.html#DoesTheGPLAllowMon...