The Wario Ware saga just came from out of nowhere. A greedy man who is already famous and popular for going on epic treasure hunts just all of a sudden opens up a factory producing mini games, things the Mario Universe already had thanks to Mario Party.
It's like if Pokemon just decides to start a game about cooking Hamburgers made out of Tauros' and Miltanks. It would be Pikachu's job to place the lettuce, pickle, mayo, mustard, ketchup and a bun all before the burger hits the end of the packing machine.
There was nothing wrong with Wario Land. People must have been buying it if it made it up to #4 and it must have been missed or they didn't come up with Wario Land: Shake It. It seems to me people buy the Wario Ware titles because it's Nintendo, nothing can go wrong with them! That's why the main Pokemon games keep selling. Have you played them all? Its the exact same story, some kid just collects 8 Badges but has to stop an "evil" team from doing something that would actually be awesome horrible but nobody learns anything in the process. Then, when they get the badges they can now battle the Elite 4 and when they do that, Battle Tower time (like the repetitive battling wasn't already there).
In addition, Wario showing himself off as a professional businessman is not what I ever saw Wario becoming. Wario is a greedy, lazy son of a female dog. Lazy people don't work for their money, they steal it. Also, to run a business, you need to be smart. When was it ever shown that Wario has the knowledge to run a bloody factory?