Some day, I'd like to see an argument supporting this.  A real one.  One where someone shows games for each of the consoles of varying quality and the costs associated with each. 

Sadly, we instead have to listen to people speculating, inferring, and generally drawing conclusions which they cannot adequately verify.  And of course, their opinion is always "definitely" the right one.

Thank you, Rol.

The industry, as Rol stated, is not full of idiots.  The high-production-value games I was referring to as "quality", are almost always targetted at demographics which fit the HD consoles better than the Wii.  Hence, the lack of "quality" gaming on the Wii, given the relative per-title/per-investment attach differences.

The 3rd parties haven't yet figured out how to invest and create a decent Wii title, from the ground up.  Nintendo's "stranglehold" on their own console results from their legendary IPs being so ingrained into modern culture, that they practically define what the "blue ocean gamer" likes, in and of themselves.  

I see it as basically impossible for 3rd parties to cook up new IPs that will be hugely successful on the Wii, at this point, relative to new IPs on the HDs.  Mario has been Mario for decades -- Mario IS the Blue Ocean, and nothing can, or will, compare to or uproot that, without the same time investment.  The available avenues are basically things that have also been ingrained into our culture as fun livingroom/family room activities -- fitness is a prime example.  Or billiards, table tennis, etc.  

Games that have appealed to the masses for generations define Blue Ocean gaming.  Mario fits that description perfectly.

Back to the OP: "Mature" titles will never have the draw (from the financial perspective of the publishers) on the Wii that they do on the HD consoles, until the Wii's marketshare hits something close to 70% -- in other words... it will never happen.  The reason investors invest in cheap Wii projects, is because they can't justify making an expensive Wii title without an IP like Mario behind it.  Its folly to believe that "Wii games" are cheaper to make due to the hardware.  

It has nothing to do with the Wii itself, and very little to do with the development cost of modern games on the Wii or HDs.  It has everything to do with the Wii's demographics.

Are you saying that 3rd party developers have trouble succeeding on the Wii because of Nintendo's first party games?

Yeah! More bargain bin efforts!

Not at all.  I'm saying that 3rd party games lack the blue ocean "punch" that Nintendo's culturally ingrained IPs have.

In any case, there will always be some "mature" games on the Wii, due to the fact that nature, and investment, abhors (or appreciate, from the investor pov) a vacuum.  The amount of turf to conquer on the Wii is lower, however, so once that market vacuum condition is removed, the investors go right back to the HDs.  Sega is basically clarifying to the Wii audience that it will always be on the lookout for the hardcore vacuum on the Wii, and that it will not simply walk away.

It would have been so awesome if Nintendo would have teamed with Sega to release Madworld. Make a black and white Wii that had a red light. Japan might like this. I'm not sure if it's released over there yet.

Third Parties are struggling on the Wii because thus far none have put a serious effort on it. Tales of Graces and Monster Hunter 3 will be the first serious third party efforts put on the Wii. Everything else up until now has either been ports or third-second tier games.

@Procastinato
I think Rol was being his usual ironic self, there, his point being that companies are losing money left and right. I don't think that they can solve all their economic troubles by developing for the Wii, but certainly a more variegated portfolio seemed to work well enough for Ubisoft.

Anyway, there's a very simple and rational reason for the Wii games being cheaper. The great cost leap between games on xbox and PS2 and nowadays HD games is mostly in the assets production.
Higher def textures, higher detail in models and animations etc. Those are a lot of man-hours that explain the greatly increased costs.
Developing on the Wii will be generally cheaper than on the HD consoles because most of these assets will take less man-hours to be produced. Plus there were also reduced costs with staff training and toolsets because the GC know-how did port almost 100% to wii development, but at this point in time that's a one-time investment most developing studios have certainly done to move to the HD consoles.

In one thing you're right though: if you consider bigger, top tier games less cost differences would apply. Hiring 5 actors and all the tools for 20 hours of motion capture will cost the same whatever console will make use of the data. Same with voice-overs, man-hours spent in testing time, server infrastructures for online gaming etc.

How come I have a sinking feeling that Sega will be abandoning serious efforts on the Wii in the future.

Not that their efforts on the HD consoles are doing them any better.

QFT... Although The Conduit will probably do reasonably well for a 3rd party wii effort, its really sad Valkyria Chronicles didn't do too well...  Half a mill seems low for that game...