I see a lot of younger people on bikes, but not a lot of younger 'cyclists'... the differentiation being the kids on bikes are on mountain bikes wearing baggy shorts etc and hang out on forums like mtbr.com etc, and are teenage boys, and 'cyclists' are roadies in lycra sipping cytomax and caring about clipless and watts and lung capacity etc etc.

I think it's a priority shift, coupled with the $$ factor.