If Nintendo does a price cut even in Japan, let alone in all the markets, it would just show incompetence on Nintendo's part.
In the business world, such drastic movements can kill a business and if all of the companies in an industry carry out such drastic measures, it can kill an industry.
So Nintendo has only been selling ~20k consoles for the Wii. Boo hoo hoo woe is them. They are constantly selling at least 45k DS systems and have been on the top of the Japanese sales chart for a while (after the MH effect on the PSP died down and the DSi craze started). And, the most important of all things, is that consoles are now the secondary system in Japan. There is a cultural shift in Japan right now and the people want to play their games, but also go outside and do something.
Right now, games are the only reason to buy consoles and/or pay attention to them. And currently, the 360 and PS3 are getting their games and are getting their respective and deserving console boosts. When the Wii gets their games, like MH3, the Wii will get the attention their console boosts.
This is the same thing when accounting "core" gamers and the Wii; when - not if but when - the Wii gets the games that garner the attention span of the "core" gamer, the Wii will get sold even more so. The Wii, as others have already mentioned, is cheap as it is. Those who say otherwise are either making excuses or seriously have spent a lot of money on other things and just wish it was cheaper so they can afford to buy another system. The only thing missing for those "core" gamers who don't have a Wii (or who sold them) are games that appeal to their interests.
That is it. It is as simple as that.