Like Wii Music and Metroid: Other M.
Why, whatever do you mean?
To create a good product, you need to invest a lot of time and effort into it, consider the customers' interests in lieu of your own, have someone behind your shoulder to tell you which ideas are stupid, refrain from shoehorning said stupid ideas into the product regardless, et cetera, et cetera. And unless the developer in question is a masochist, that generally means no fun time for them.
Wii Music and Other M are the most notable examples of developers opting to "have fun" instead of doing any of the above. (Except for, arguably, the first thing) Both were commercial bombs and are well-nigh unanimously considered the low points of their respective series.
Not saying that developers can't enjoy their work. But given the chance, they usually put their personal enjoyment and interests above the consumers'. And, really, who wouldn't in their position?
(I had that all phrased much more eloquently, but blackouts are frequent here)
I won't talk about other-M, I'm not a fan. I'm a Metroid fan that is definite, but I own other-M and haven't enjoyed the little I've played of it.
Wii Music, though. That's not a good example. When Miyamoto puts his heart into something, he generally knows what he's doing. The thing about Wii Music that we don't see is why it failed to meet expectations. We know it failed, but we don't know why. To say it bombed is a total overstatement...
I know, I know, if you compare it to Wii Play, WSR, etc. etc. it's low. But you know what? Wii Play was a piece of garbage. People bought it in truckloads, but big question. Who bought Wii Play 2 (Motion)?
That's right, nobody.
So much for listening to consumers. They thought they were listening, sure. Consumers said "Give! Give!". Then when the 2 came out. Oh geez I won't even offer a proportional success value it'll be ridiculous.
We can twist facts until we're red in the fact (and this goes for Rol too), but fact is Miyamoto generally knows what he's doing, the guy is full of creativity and ideas that lead to success. Some less, granted I'll admit, but in general he does a fantastic job. Other M has nothing to do with him as far as I see it.