Sadly it's probably because of the economy. GENERALLY speaking, skiing is still seen as a more fluid classy sport associated with the high/middle class. As big as snowboarding is now, i think it's more casual. A lot if riders I know have good jobs and rude for fun, rather than also getting brought up in those family ski weekends.
Point is, if the upper half if the social class primarily skis, which may be a safe assumption, and all price point are going up, skiing and riding has become significantly more expensive. And if more riders than skiers are opting to spend there money elsewhere, rather than on weekend trips, that'd explain it to me.
Ride as much as you can. It's good for the soul. But the whole ski/snowboard separation hate is just lame nowadays. Who cares if there's more skiers than riders. We're all there tk enjoy the day