Why are some Japanese games only localized for Europe?

I was browsing through the e-shop today and I saw a game called One Piece Unlimited that seemed interesting, so I started searching about it on the internet (using my PC since the 3DS browser is garbage). One thing I noticed is that the game was only released in japan and PAL teritories, and that reminded me of other japanese games in recent years that did the same.

I am european so it doesn't affect me, but I was wondering why do they do that. They are being released in the UK so they already have an english translation, and isn't USA a bigger market than Europe?

@Alexandru:

Maybe the marketing and/or licensing in the US is more expensive than in Europe? Or japanese games sell better in Europe than in the US? Hell no idea.

I don't know about in general but with it being One Piece there might be licensing issues.

One Piece is really popular in European countries, so there's more of a market than America. The 2 unlimited cruise games were originally disc based games for the wii. Doesn't NA have some sort of rule where all disc based games need to have spoken English language, or is that only PS3 games?

Also, the One Piece anime is licensed by Funimation in America. It'd cost more to dub the game than they're willing to pay since outside of Japan it's a niche game.

@Nintendo of America said:

Because you touch yourself at night.