For Example
Shin Kamen rider had some really violent moments which can be seen right here:
http://www.youtube.com/watch?v=f6A_NtllQO0
Well, Shin's an exception: it's pretty much the only legitimate tokusatsu aimed 110% for the adult fan. It was a V-Cinema celebrating the 20 year anniversary of Rider by offering up a darker take on the classic Rider story, targeted to the then-fully grown ones who grew up on the original.
But...
I didn't want to get into this once again (it's a topic that never dies, it just comes back, bigger and stupider than before -- like Jason Voorhees), but...
"Sesame Street." "Doraemon."
Those are kids shows, through and through. There's nothing on a higher level for an older person there to enjoy. Superheroes can obviously have a broader appeal. I don't think Ultraman, Kamen Rider, sentai, or metal heroes deserve to be written off as just "kids stuff" -- that's the narrow thinking that writes off material like Batman and X-Men as just "dumb old kids stuff." That's the kind of thinking that numerous writers and talents in the field have struggled like sons of bitches to escape. And no matter how mainstream the genre gets or what it accomplishes, it still gets generalized.
Superheroes -- not to mention certain pieces science fiction -- are seen by a large group of the population as just lightweight or "stupid kids junk," but anybody who has made the attempt to gaze past mere labels can tell you that there can be more to the good ones. It undermines what talents like Stan Lee or Shotaro Ishinomori or Masaru Igami or Hirohisa Soda or Toshiki Inoue have accomplished. They want their tales to appeal to a mass audience, they often achieve it by telling unique stories that don't talk down or pander to one set...
...of course, to get their stories heard, they must partner up with some more shadowy folk. Some are good guys -- some are like Toru Hirayama, Takeyuki Suzuki, or Shigenori Takadera and are on the same wavelength with getting that story out with least amount of interference. Some are dubious, like Shin'ichirou Shirakura or Jun Hikasa, often blinded by greed, and pollute the product with stupid things to make it more commercial, knocking it down to the lowest common denominator just to make a sale...
Everything in the film and television medium comes down to merchandising, it just depends on how well it's handled. But you can't write off all superheroes oriented tales as just "kids stuff," just as you can't say that about animation.