Here's my take on the whole 3rd-party situation with Nintendo.
Developers like to make games for the most capable hardware, that is proven with all the support that the Xbox 360 and PS3 receive. Both the PS3 and Xbox 360 have similar hardware, so developers find it more convenient to make their games for those systems. And because the Wii is so underpowered compared to the Xbox 360 and PS3, developers don't want to bother with "downporting" their games to run on the hardware.
Developers also want to make games for the largest install base. Combined, the Xbox 360 and PS3 match the sales of the Wii, so of course developers see a larger market with those two consoles. And the fact that the Wii is so underpowered basically killed any enthusiasm from 3rd-party developers and "core" gamers. It's a lose-lose situation for Nintendo.
Despite Nintendo's best efforts, they failed to convince 3rd-party developers that making "core" games on the Wii was a cheaper and more viable alternative to the ballooning budgets of the HD consoles. Nintendo and their 1st-party studios made fantastic games on the Wii, ranging from Super Mario Galaxy to Zelda: Skyward Sword. 3rd-party developers could have tried to match Nintendo's standards, but they kept viewing the Wii as a casual-gamer's console, filled with party games and waggle controls.
This is partially due to Nintendo's early marketing campaign that showed families enjoying party-style games. Anyone remember the "Wii would like to play" commercials? But those aren't the only games Nintendo made. Games like Metroid Prime 3, Super Mario Galaxy, DKC Returns, and others proved that there could be more "core"-oriented titles on the Wii. And Nintendo even created the Classic Controller Pro so developers wouldn't have to shoehorn waggle controls into their Wii games, yet hardly anyone utilized that controller.
Nintendo's increased focus on motion controls and family-friendly games killed the Wii brand in the eyes of 3rd-party developers. They couldn't get that negative stigma from their minds, and kept thinking they had to create party games to cater to the casual crowd. As I said above, Nintendo showed how both casual and "core" games could work on the Wii, but 3rd-party developers were too jaded to catch on.
Microsoft and Sony saw the casual market that Nintendo had captured with the Wii and tried to replicate it. The results were Kinect and PS Move, respectively. Kinect was hugely successful, while Move was lackluster. Despite Microsoft and Sony's rampage into motion-control territory, 3rd-party developers continued to make "core" games for the PS3 and Xbox 360.
Long story short:
- Nintendo makes a console that focuses on casual family-friendly games, developers catch on and start making piss-poor waggle-fest games
- Nintendo comes out with the Wii Motion Plus that allows for more accurate motion controls, sdevelopers largely ignore it
- Nintendo makes the Classic Controller Pro to appease developers that hate motion controls, developers ignore it
- Metroid Prime 3, Wii Sports Resort, and Skyward Sword show how motion controls can greatly enhance gameplay, yet a majority of developers ignore them
- Nintendo then changes their stance and makes more core-oriented games, developers ignore this and instead keep making casual games
- Microsoft and Sony enter the motion-control market with Kinect and PS Move, developers ignore them
Developers seem to have this weird claim that they can't compete with Nintendo's games. Does this mean quality, or sales wise? In either case, they just need to be more ambitious with their games. Treat Nintendo consoles the same as the PS3 and Xbox 360. If they put the same effort into making games for Nintendo systems, then maybe they'd see more success. Many 3rd-party games are arguably more ambitious and complex than Nintendo games, yet those games hardly come to a Nintendo platform. Games like Uncharted and Metal Gear Solid prove that developers can make amazing games if they try, yet they hardly put the effort on Nintendo platforms.
And here's the main thing that bugs me: No matter how many times Nintendo tries to show how normal games are done on the Wii, developers ignore them and continue to make crappy kiddy/casual games with horrid controls. Nintendo just can't win, it seems.
This brings us to the Wii U. Nintendo has now decided to recapture the market that MS and Sony "stole", the "core" gamer. The Wii U console has all the HD power that developers have been clamoring for, and the controller has everything a normal controller has (in addition to the large screen in the middle). Whether this is enough to win back 3rd-party developers and "core" gamers remains to be seen, but early reports have been positive. The backwards compatibility with Wii Remotes and accessories shows that Nintendo hasn't forgotten about the casual market. With all of these things, hopefully casual and "core" gamers can all see the value and potential of the Wii U.