I wonder whether you would be lucky if Witcher 3 was only released in Polish. I mean, you could learn the language just in a few months by watching Polish movies and TV series, or not?
I would have no problems with that, coz im polish
But this is kinda weak argument in general, because polish is one of the hardest languages in the world. And english is one of the easiest. Anyone can learn basic english in ~3 months. My friend's mother recently did this, and she is 58 years old. And once you know basics, you can easily improve your understanding by reading books, watching TV shows and playing games. I've learned it that way. I loved fantasy books, and many of good titles weren't translated yet, so I've tried to read them in english, even though my knowledge of it was very basic. Was damn hard at the beggining, but after few weeks I've realized that suddenly I'm doin it without much problems, because even if i didn't understand some words, I could still pretty accurately guess the meaning of the whole sentence. Reading like this, I've learned more english in 3-4 months, than in a dozen or so years of school education.
Though of course, while playing games/reading books etc. is possible with basic english, and it can be a good way to learn, it is nowhere near comfortable, and there is no reason to force people to do it, instead of just letting them enjoy playing translation. It should be their decision, in which language they want to play, and everything I've said is definietly not the excuse for poor translations.