I'm sorry, but I don't see a dying hobby at all. Is it as huge as it was in the '60's? From what I've seen and heard, no it isn't. But what it lacks in sheer size, compared to where it used to be, it more than makes up for in diversity and subject matter. So, yes, I see a more focused (selective, perhaps?) market than in the past, but by no means dead or dying.
People have been building miniature replicas of vehicles long before the invention of the old annual kits... before cars,even. That's going to continue, whether kits are available or not.