I'm not sure how much ground this argument holds.
Two things.
1) Hardcore gamers on the Wii do not sell as well as they would on the 360 and PS3. Case in point = The conduit, madworld, punchout, etc etc. It is not like any old development studio can make a game for the Wii and be rest assured it is going to be a success. The only games that really thrive on the system are casual games, party games, RPGS, and Nintendo exclusives. It forces developers to have to make games that, quite honestly, aren't desired on the other two systems. I am aware that Natal was made to appeal to the same audience that the Wii appeals to, but honestly that leads me to my second point..
2) Wii didn't take any bullet. If anything it saw the bullet coming and built a hole through its wall to let it pass through painlessly. What the system did, is rejuvenate a company into the powerhouse it once was. It is VERY hard to hate Nintendo as much as people hate Sony and Microsoft, and even now people talk about MS being the arrogant one even though the Wii has a 20 million lead on the 360. Unfortunately though, the Wii changed the gaming landscape , and some of it is great, and some of it not so much. The first evidence of these changes can be found in the new Madden 10. Where both the 360 and PS3 versions are gritty, amazing looking, complex, and authentic, the Wii version has stretched out cartoon characters, 5 on 5 football, and an "I win" button. Why? Because EA, for all of their shortcomings, has figured out that the key to the Wii is to "lighten it up". Unfortunately I sense a trend here that is bound to continue.
I'm not bashing the Wii at all, but when I play games like Halo and Bioshock, I have to wonder, 5-10 years down the road , when the next round of systems have come out, just how much the business model is going to revolve around the groundwork the Wii placed. And whether or not "Serious gamers" are going to have a place to rejoice, or mourn