In Europe at least, there's a translation barrier. If there's an english translation already, that covers England, but nothing else really. Lots of people do speak english, but it hurts the market that much more. There's also the dozen different ratings boards, one of which (Germany) forces games to be censored in certain (rare) cases. In Switzerland (where I used to live), lots of people my age would refuse to play a game in English or Japanese or whatever on principle even if the French dub was horrible.
