It's not that simple for developers.  They sunk all their investments into HD game development at the beginning of the generation, and were either unable or unwilling to change direction when the Wii suddenly seized the lead.  The only remaining tool they had at their disposal was to attempt to convince the audience that HD was the way to go.  To that end, industry developers, analysts and media alike built up a sense of elitism aimed squarely against the Wii, which only served to further alienate the 'core' gaming community from entrants coming from the larger market.  The end result is that they can't support Nintendo this generation, because it would involve going back on their words (and by this point, it's too late for this generation anyway).  Considering that they choked off any new blood from entering their market segment, this will result in the destruction of many third parties, and a drastic swing in the long term balance of power of the console wars back in Nintendo's favour as new developer entrants are heavily restricted by the ever-increasing cost of entry to the gaming market, and the survivors attempt to recover from this generation.  In that, it matters little for Nintendo if third parties never figure it out.

I'm not sure many hardcore give a damn about those franchises... or at least those who don't already own a Wii.

Most of em were PS2 only owners afterall.

wait what....? Most of the "hardcores" out there were ps2 only owners???