Because Dragon Quest games are big so it takes a lot of resources... and since it doesn't sell like crazy, there isn't much need to.

Part of it comes down to Nintendo can only localize so many games at a time. Platform and party games like Mario and Kirby may not require a lot of work, but Super Smash Bros does, as does their work with Capcom bring over Monster Hunter. Not to mention they have a number of their own games of their own coming down the line you have Legend of Zelda: Tri Force Heroes, Fatal Frame: Maiden of Black Water, Xenoblade Chrocnicles X and Yo Kai Watch later this year, plus next year will have Fire Emblem Fates,I can't even imagine the difficulty SMT x FE or whatever it will be called outside of Japan, hopefully Zelda Wii U, maybe another Pokemon game and possibily Bravely Second as well. It is not in anyway fair at all for Nintendo to have to pay to localize and distribute yet another company's  major franchise game because said company doesn't have faith in their own fans in other western countries on a major platform yet will drop games out on the Vita or app markets on their own with no hesistation.

I love what Nintendo did for Dragon Quest on the DS, hell they made me a fan of that franchise and I wish they could do the same on the 3DS. However, responsibilty for bringing those games outside of Japan shouldn't fall on them unless Square Enix is willing to sell them the franchise or a major portion of it, guarentee future games are exclusive to Nintendo platforms like the deal they got with Fatal Frame. Square Enix releases games in the West all the time, they could easily do the same with DQ and after the success that was Bravely Default, they themselves implied they had learned the lesson.

But instead it is all talk, all their 3DS games that Nintendo doesn't bring over themselves are locked away in Japan meanwhile they show more support for the Vita directly then they do the system that is killing it globablly. A few low budget Rhythm Games does not equal support, Square Enix needs to step up, if Atlus can bring over what it does with only their $10 price hike and do well, Square Enix has no excuse.

Oh, I totally agree. I put the blame fully on Square Enix. It's ridiculous how little they support the platform outside of Japan despite its potential. Nintendo can only do so much.

The fact that they're willing to localize two Theatrythm games and not mainline Dragon Quest is disgraceful. Bravely Default selling more in the west than in Japan should tell them something, but it seems Kingdom Hearts 3D will be the only big game we get from them.

They have a personal vendetta against me. Sorry guys.

Perhaps it's the same reason why Square Enix doesn't localize these games. It's just not worth it

Just check "screwed by the network" at TV Tropes. You can find this little gem there about DQ VII:

Square Enix's American branch seems content with giving the Dragon Quest series the shaft, with Nintendo ultimately stepping in to localize the ninth and sixth installments, not to mention DQ Monsters: Joker 2.

And Nintendo is localizing Bravely Default, the Spiritual Successor to Final Fantasy: The 4 Heroes of Light, as well. Square apparently had no faith in a Western release despite the game's absolutely massive success in Japan and the relative lack of role-playing games on the 3DS platform.
It's gotten to the point of absurdity. Some insider info revealed that SE outright blackmailed Nintendo in order to prevent the localization of the 3DS version of Dragon Quest VII by threatening to strip Nintendo of their rights to localize Bravely Default if they decide to localize the DQ7 remake.
Much of this comes from the fact that Dragon Quest have historically been sleeper hits, rather than immediately successful in the US. Demand for the series has increased, but it isn't the Cash Cow Franchise in the US that it is in Japan.


Read more: http://tvtropes.org/pmwiki/pmwiki.php/ScrewedByTheNetwork/VideoGames#ixzz3dfHF0S42

So yeah, under such circumstances we can only hope SE will see the light

Huh!?

That makes no sense. Square Enix is the IP holder for Dragon Quest. No other publisher, no even the big 3, can make decisions on localization/distribution actions for IPs not owned by them. Period. The deal here is that SE was not satisfied with sales of previous DQ remakes and decided not to take the risk, Nintendo did and SE got paid to do nothing. That is how they want to keep their relationship with Nintendo. The've become content with that formula. 

It does make no sense.

And still, Nintendo had been localising  a bunch of SE games just because they didn't want to do it themselves for whatever reason their higher-ups saw there. Sure, DQ is much less popular in the west than it is in japan, but when the console producer is making the localisation themselves, why threaten? After all, SE would still have gotten money out of it, not risked their IP, and for zero effort even.