For a Nintendo IP.. maybe not that important because an IP can be successful on a fairly small install base. Success is however relevant.
From a business perspective the install base in very important, it's the difference between making relative peanuts (Wii U) vs printing money (Wii).
While I see your point and to a degree you do make some sense, ALL businesses involved in mass market production will prioritise the install base because that is where the real money is.







