Because they've always happened every so often. Like with Wario Blast or Wario World or Wario Master of Disguise, and with both Wario Land and WarioWare not doing so well recently, perhaps Nintendo will try something new with the character and franchise.
Or just farm it out to some third party, it's a 50/50 thing at this point...
Well, they pretty much ruined his imago with Super Smash Bros Brawl and the new one now. So that's a problem... He isn't really usable any more in any normal, not-gross game.
You know how Wario rolls, that reminds me of Sonic. They should work together. As long as it's not too obscure and is perhaps a bundle with a system to get people to try it (or at least make the game be as addicting as Tetris). Maybe he'll go back to final boss status and grow more popular later in time. But imo obscure games make the character look bad unless it's an already popular franchise. I've got it! Wario Pinball.
A Grand Theft Auto type of game where Wario is free to roam a world and do whatever he wants to make a ton of money. Be it crime, odd-jobs, treasure hunting, you name it! Maybe someone asks Wario to help him find a ruby and will pay him handsomely. Wario gives him the ruby (getting the reward), and then steals the ruby back from him!
