A couple of things. First: I believe that Revell tried to appeal to the younger builders with the Ford Focus, Honda Civic and Acura Integra kits. I don't believe they did very well. Don't know what to make of it - just putting it out there.
The other thing is in general, the younger crowd aren't as passionate about cars as we were. I mean when I was of age everyone and I mean everyone, boys and girls alike, wanted to learn to drive and wanted a car. Virtually every male was a car nut to some degree. Now I know of whole families where the kids have not learned to drive. They could care less about cars as long as someone has one somewhere to drive them to where they want to go. To them a car is like a stove, an appliance that somebody else uses to serve you.
Now don't get me wrong, I know there are plenty of car crazy young people as evidenced by the younger model builders on this board but it's not as pervasive as it was 30 years ago. And this lack of car passion that we had then is bound to affect car modeling now.