The problem is GPL(and by extension BSD and zlib style licenses) might end up being hated by devs/corps/whoever because it cock blocks a platform to ensure freedom of users that already chose a walled garden and do not give remote shit about privacy, freedom or what language, tech, OS or license their software is in...
Also no-one-tells-me-what-to-do attitude comes into play, that's one of reasons I dislike GPL. If I got good money out of SFML powered stuff I'd probably donate to it(and to other libraries I use too, of course) a tiny bit of my profit and open the code a while later to help others(and of course, in turn, make SFML better, more popular and make my experience with it more marketable and profitable, after all, most of these profits would go to me, I'm not charity), but just because I want to give something back and not feel like a leech, not because I was forced to by annoying license that protects freedom of users that don't give a shit anyway.
But if forced to by something superior(ie. id tech games that use it for free) or by own choice(ie. Frogatto) GPL for games makes sense, no pirate is going to compile your game and pirate assets, they will just pirate (cracked) exe and content together and never look at the code just like they would with a closed source game.