Probably because they only release some games once a generation and the reasons everyone else said.

This and this.  Iwata adressed this once I believe and it is about perception of value for their software. 

Here is an article where they touch on it, but are mostly talking about retail and digital prices being the same:

Nintendo president Satoru Iwata has explained why its digital games are not less expensive than their boxed counterparts, which must be manufactured on discs and shipped to retailers.

"Although the mainstream idea regarding the digital business in the industry before we actually started selling software in both digital and packaged formats last year was that the digital version should or must be priced lower than its packaged counterpart, we decided that, since the contents are the same, the company would offer the software at the same price, be it the packaged version or the digital version," Iwata said during a recent investor Q&A session.

Iwata explained that this price parity is the result of Nintendo wanting to make sure the company's software, released digitally, is not devalued compared to the boxed product.

"This is because we want consumers to value software as highly as possible and because we have been trying to heighten the value of our software whenever we produce it," he said.

Credit GameSpot

I guess their games still continue to sell at that price, and that Ninten doesn`t like to reduce the price on their games. If it continues to do well, why drop it? : x

There is basically this price protection clause thing that you can pay for the prices to not be altered by the retailers. Nintendo is highly protective of their prices and their games are usually always priced at full unless they explicitly want the price cut.
Of course, there are exceptions to the rule. But that is the main reason why they arent lowered.

Its quite smart of them i think, but in a way i am sad as a customer. I would buy more Nintendo games if it wasnt for that.

Ask Nintendo I suppose.

Ocarina of Time 3D is out of print, for whatever reason. If they still kept stocking it, it would keep selling.

Bang up idea. Let me get Iwata on the phone. brb.

Because money.

So I wouldn't ever get a Nintendo system or Nintendo games. I vote with my wallet.

That, or Nintendo thinks keeping prices high is their best bet at profiting.

Yeah, it is really weird. I had to buy it used and it was basically the cost of a new game.