Well, others have addressed this, but they actually don't end up not localizing many great games. There are a few games with potential that wasn't met that they don't localize, but even if they did for a small group that wanted the only result is that those people would be disappointed. Not doing that is actually a good decision on their part. Games like Fire Emblem show that if Nintendo thinks they can sell a quarter of a million units and make most of those buyers happy they will. But they won't release a game that will sell that little and make more buyers unhappy. And that means that the Nintendo brand name remains strong. Also, if it's not going to sell enough to make the effort worth it, if it's so niche that hardly anyone will buy it no matter how good it is at what it does, then why should they release that either?
Now, there are a couple of unreleased titles that could actually perform up to standards. Like, litterally, about two. Maybe three. That's a very small amount compared to many generations of old. I can name three SNES titles off the top of my head that'd make those criteria (none published by Nintendo), and that's without trying. Tripple it for Europe. On the otherhand, I've played a few games Nintendo didn't take out of Japan (at least for some time) and rarely did I feel like the world missed out on something. The thing is, they know what's good about a game. And they know when there's not enough good to put it on the market. Games they've passed up on in a very final way have already been noted by people who played the imports as not that great. Maybe they appeal to a niche audience or maybe they are so buggy it ruins the experience. Whatever it is, if the game wasn't released in the last 12 months Nintendo propabably had a pretty good reason.
Seriously, if you want to play these games, there's obviously a way. My guess is that no matter how much you enjoy storyline, most of these games are either going to be too bad or too niche for you to actually enjoy the game part. If the gameplay falls into place for you, I hope you don't like storyline much because it's probably pretty bad in Japanese and not likely to get better in English or any other language due to the damage that can be done to concepts in translation.
You do not have the right to never be offended.
