I think the Yagudin/Plushenko rivalry helped set the bar very high in the men's and the top guys know that they need to reach a pretty impressive standard to really compete. And though both Plushy and Yagudin won championships as teens, I think both peaked in their twenties. Is the toll high-level figure skating takes on a girl's/young woman's body is more severe, leading to shorter careers and ultimately to more top competitors retiring before realizing their full potential? Imagine if Yagudin and MK had retired at 18, after Nagano 98: although both were already accomplished skaters at that age, esp. Michelle, would they have been as memorable to us?
That having been said, there are currently some very impressive female skaters in Finland (as Joesitz said) and of course in Japan, and I think being in such a competitive environment pushes young skaters to excel even more.
BTW, Medusa's right about Joubert/LambielVerner not coming up through the junior ranks. Joubert's placement in the one Junior Worlds in which he did take part was 15th, which definitely wouldn't have stopped the presses. But I'm not sure the three of them were that successful as seniors their first few years: Verner competed as a senior for years before really making a splash at 2007 Euros, and Lambiel won his first major medal of any kind when he became the 2005 World champion, aged 20. Joubert was medalling at Europeans, but had only one podium finish at Worlds as a teen (a silver in 2004, when he was 19).
My theory is that the society doesn't necessarily need to have a whole lot of genius ppl. Only several may cover the needs in the field.
Good point, Bennett! The same is true for other athletic and creative endeavors... I'd be happy to have a lot of genius medical researchers, though.