Hm. It was a funny video, and I see the point your making here. A lot of kids pick up controllers at a young age, and some of the characters, items, and plot may not be appropriate.
That being said, most children I know personally witness things worse than some of these in everyday life. It would be almost acceptable in some parent's eyes for a kid to play Majora's Mask at a young age. I don't exactly think that kinds under the age of eight should really pick up MM (using this as an example) and playing it. Games I play now give me nightmares: imagine what it could do to even younger kids.
Still, I think children should be allowed to play Zelda. It has become a large part of my life, and as I still am in my younger years, I think it counts. Zelda is directed towards all audiences, not kids under the age of twelve. My parents still play Zelda now, and my little sister is starting on OoT soon.
Overall, my point is that Zelda games are acceptable for younger children. When they reach they age of being able to navigate a game pretty well, they should be mature enough to understand the content too. It's not a kids game either; it's a feel good game series for any age.