"I don't think I ever saw a single commercial for Halo at Xbox launch..."
Not only were there ads like Deguello mentioned but those ads showed exactly what Nintendo's never show yet many of us feel they should. The Halo ad had quite a lot of gameplay footage (why not? Graphics are the Xbox's specialty) and tons of "BEST GAME EVAR!!111" quotes from reviews and such.
"has it ever dawned on you that you may be a little more out of touch with those younger than you than you thought? Or that YOU aren't as cool, popular, or in-style as you previously thought(speaking to those that are younger)?"
That's very likely. I don't fall for obvious attempts at advertising trying to sound cool and never did even when I was a kid. But I was never really cool as a kid so I was kind of outside of that culture. I do tend to assume that most people's reactions to ads are similar to my own but that's realistically not the case. So this ad might work despite it, in my mind, being incredibly cheesy and forced. It does have a lot of the problems that Cube commercials have and it's very easy to prove that Cube commercials don't work. The sales, or more accurately LACK of sales, backs that up. So does that type of advertising work for portables but not consoles or are GBA and DS sales unrelated to ads entirely?