Bionicle was a unique phenomenon when it came out: I had friends who had given up the well thought out military fantasy of GI Joe at age 12, suddenly buying Bionicles after college graduation. I'm still not sure why this was: The storyline was hard to access and inconsistent.
Transformer collecter myself (and a subtle one too), so I certainly don't accept marketers' age recommendations. In fact, in some cases, they're completely arbitrary. Are that many primetime "adult" oriented shows really more intelligent than well-done "children's" cartoons?
Example: In one TF cartoon, the Autobots were mediating peace talks between 2 warring planets, only to learn that some other aliens called Quintessons had started their conflict just so they could sell increasingly powerful weapons to both sides, hoping they'd exterminate each other before anyone knew. Tragically, that's often the role that the military industrial complex plays in real life conflicts, but I can't think of many "adult" dramas that acknowledge this. Can anyone else? Seriously, let me know; I watch a very narrow range of television.
I can think of one instance where the usual gender-interest crossover was reversed on a large scale: In the mid '90, DIC's US broadcasts of Sailor Moon had a huge closet following of teenage boys, because there was no other anime airing here at the time, and it was nothing but hot schoolgirls in miniskirts fighting monsters that were sometimes even hotter women. Oh they TRIED to market it to 8-year-old girls, but that hardly obscured what it was. If they'd done the toys more like action figures instead of Barbies with poorly-done cloth outfits, inaccurate anime faces, and rooted hair, they might have outdone '90s sales of DBZ figures, but they just had to follow the rules of gender-targeted children's marketing all the way to the grave.
Cartoons actually weren't targeted in this way until the '80s, when they became so important in selling toys.
I've always been proud that my interests aren't dictated by what I'm "supposed" to like. Hell, the later Transformers comics actually gave me a more mature view of the greater universe than most people get from actual religion.
"Hah! For all their supposed omnipotence, even gods can be conned!"
-Alternate-Reality Galvatron, 1990
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No one in the world ever gets what they want,
and that is beautiful.
Everybody dies frustrated and sad,
and that is beautiful.
-TMBG