And how do you suppose they do the former, given the massive differences in capabilities between the Wii and the other two? The only realistic result would be a pure downgrade and blatant compromise, which would be seen as such by the public, and as a lazy effort destined for failure by Wii fans.
No, it would have to be the second, which would then essentially be an exclusive. It would have to be marketed hard, have a strong appeal and be well designed, and all based on a hunch that it will pay off greatly, enough so to justify the resources put into the product. Of course, it could be that the market just plain doesn't desire to have these types of games on Wii, and would rather go for the HD solutions in the case that they do want these types of games in the first place.
Besides, wasn't Dead Space Wii built to take advantage of the platform? It's a rail shooter of sorts, but I hear it was quite good at what it did, and it was an original, well marketed product for the Wii. See, it wouldn't matter what they do, it would never be good enough. Developers and publishers would be lashed heavily by internet critics, who never once think to perhaps redirect some of the "blame" towards the platform designer who decided to force a unique and incompatible solution into the traditional mix. Not everyone wants to be shaken up, least of all members of an already shaky industry.
And no, what I wrote wasn't really sarcasm. Since some people, such as yourself, are so confident in this magical solution, I suggest that you pool your money together and help fund a project of the sort. Perhaps this level of confidence would rub off on the publishers, eh?