Wishbone: I think in this case the question is probably more likely "What brings in the most money? Selling 10,000 copies of a WiiU game or selling 10,000,000 copies of a multiplatform game at 1/10th the price?"
snowkatt: yes but where wil it end then ?
if the mobile games make more money nintendo ceases to be as an entity
nintendo has always clutched on to their own identity with their own hardware
they now stand to possibly become the next sega
and see how well that turned out for sega
You absolutely cannot derive a general principle from a single case. Yes, Sega certainly went downhill since they ceased to have their own hardware, but that absolutely does not mean that ceasing to have their own hardware is the primary (or any) reason for their decline.
By that same logic, the WiiU should have been a smashing worldwide success, seeing how making a motion control based console worked so well the first time. It wasn't, because the Wii wasn't a smashing success because it had motion control, it was a smashing success because it was a new concept with a lot of novelty value. The WiiU wasn't.
Nintendo's greatest strength is their IPs. Restricting those IPs to their own hardware platforms has also restricted sales of their games to the people who happen to like their hardware platforms. As the popularity of their hardware platforms declines, so does their potential target audience, unless they are willing to use their IPs on other platforms.
Could this spell the death of dedicated Nintendo hardware? Certainly. Would this automatically mean the death of Nintendo? Not by a long shot. I'm pretty sure most of Nintendo's customers are in it for the games, not the hardware. Likewise, I'm sure lots of people who are not currently customers would actually like to play some of their games, they just don't want to buy an additional hardware platform to do it.