With any business, the question is "where is the best investment of available resources?" That's where the Wii ran into a harsh reality. The smartest allocation of resources was almost always with development that could be applied to *two* consoles instead of one. In addition to that, the Wii's virtual installed base for most games was much less than it's actual total installed base. Even with all the people who owned a Wii, the realistic proportion who would be interested in a core game was much lower than with the PS3/360. It's easy to understand why the Wii suffered in terms of third-party support and it had nothing to do with grudges or conspiracy theories.
With the Wii U, we're seeing something much more normal, which is that developing for the existing gen is still the most economical option. Right now, with it's rather meager installed base, extending development time for a Wii U version just doesn't make much sense. If you want to make money with a game this late in this generation, you're going to try to release as soon as possible. The alternative would be to follow up with a later Wii U release, but honestly, that hasn't gone over very well so far.
I've said this many times, but right now is just an awkward period. We won't be able to judge properly until at least two members of the next gen are out. Also, I still say that Wii U owners who want third parties on Nintendo systems had better buy games like Colonial Marines, because other publishers are likely to be watching those titles closely to see if the Wii U turns out to be another "Mario box", where non-Nintendo releases fair poorly.
