I understand your point, but ... Mario. They brand so many things as Mario. I'm surprised Pikman wasn't a game where you control a bunch of miniature Mario pawns. I'd bet anything it was considered. And how Animal Crossing escaped Mario branding I'm not sure. Mario Crossing sounds so very Nintendo. Honestly, that's a read turn-off for me, especially since the Mario characters are so flat and uninspired. It just feels like a complete absence of creativity.
I guess I shouldn't argue with success, though. I think it's entered Pavlovian territory at this point. People would buy a Mario game about mucking out stables or sorting garbage and they would decide they liked the game even before they played it. I'm sure Sony or Microsoft would love to have a brand they could exploit to that level.
It just seems kind of blah to me to start with "OK we need to make another Zelda game, any ideas?" or "someone had a good idea for a game, let's make it a Mario title". You know? I don't necessarily blame Nintendo for milking those cows but it's not a practice that appeals to me, either.