I don't like the term 'kiddy' when applied to Nintendo. Not as it's being commonly used.
I do think it's correct in the sense that Nintendo targets a younger audience. But they're not aiming at children only.
I do like the term 'casual gamer'. Not because I am one -I'm hovering in between, actually. But because it describes a certain audience that likes to play games just for fun, when they have a little time for themselves, and who want a fun experience. Where a hardcore gamer deserves to get the cutting edge games, and the best experience they can get.
Metroid Prime? Mad World? No More Heroes? Try and tell me with a straight face they're the best modern technology can produce. But you can convince me they're a different experience.
So there, if you'd tell me Nintendo is only for kids, I strongly disagree. If you tell me Nintendo isn't for the hardcore, we agree.