I'm going to overanalyze this for a minute: (Gomen!)
You ask Why is Pokemon frowned upon here yet DBZ is "cool"?
Some differences that I see apply to general Anandtech readers -
Pokemon is aimed at a younger audience (pre- to mid- teen), and the storylines
tend to be simplified to explain the world in ways that the main characters
(Ash and Misty) can understand.
DBZ is aimed at teen to young adult viewers, and more time in the storys are
spent on character development and building suspense for the big battles than
on trying to explain concepts that most of the viewers are already expected to
understand. (One of the reasons it is also referred to as Drag-on Ball Z)
Pokemon characters are rarely hurt seriously, and those that do get hurt are
back to normal by the next episode. Team Rocket gets blasted so much you would
think they are the main characters of the show.
DBZ characters can get hurt (phsysically and emotionally), maimed, and even killed.
The main Villians and Hero's get brought back one way or another to move the
plot along, but a lot of people die and never come back. This theme
makes a better impression on viewers who can learn to appreciate not always
having a happy ending.
Pokemon was designed as much to sell cards, plush dolls, and other merchandise as
it was to tell a story, hence a lot of the elements of the show are recent
creations of the writers imagination.
DragonBall was an adaptation of the old legend of the Stone Monkey, and carries
a lot of elements of eastern mythology and "classic" stories as the underlying
framework of the show. DBZ moved away from some of that, but still relies on
much of the formula established by the first series to maintain some of the
early character relationships.
Pokemon is on "Kid's WB", while DBZ is the flagship of Toonami, an effort by the
cartoon network to show animation (primarly anime) that has more of an appeal
to an adult audience.
Similarities:
Both series deal with characters on a quest to improve themselves, and in
both they face fantastic situations in trying to accomplish simple tasks.
Both use super-psuedo-science to allow the characters to get thru the
episodes without having to bother with those pesky laws of physics.
Both involve characters that viewer have mixed feelings about: Vegita
is often considered more cool because he's such and arrogant badass; and
I sometimes wish Ash would buy a few more clues.