Game developers running businesses in the form of partnerships or LLCs are free to make choices based upon quality and creativity.
The executives and management of corporations, however, are not free to choose quality and creativity unless it also, in their business judgment, makes the most money possible for the corporation. They literally are not free to choose anything but profit. In their discretion they can consider things like the long-term benefits of maintaining a brand by producing quality games, but then again they are pressured to produce maximal profits in the near-term, however they can.
It's the business form. It likes money, and where money pulls away from quality, it chooses money. This is what Nintendo has done in a sense, though their own games are still pretty well made: they chose money just in the sense of successfully gravitating to an untapped source of demand (casuals) only tangentially related to their audience in previous generatiions. Yeah, they make money nowadays. I tripled my money in Nintendo stock a couple years back, yay for us. But as for playing a Wii...not so much.
