Well, hmmm... of course. It's only common sense isn't it? Unless it's been said by Miyamoto himself obviously. Videogames are great and all but going outside once in a while doesn't seem like a bad idea at all now does it? (Just be sure to evade those killer trees, they'll hunt you down... seriously).
Anyway, regarding the GAF comment, well there are a lot of people that take these type of quotes too seriously and try to derail the thread in which it is posted; I consider NeoGAF to be my favorite forums (Aside from a private one I attend to), but yeah just like in every other community out there the Gaming Age Forums seem to house a lot of 'strange' people lately. Neverthless I enjoy it, and listen to Miyamoto's advice kiddies! :P