Thanks for the various opinions, facts and other comments on this subject. I am (as usual) especially impressed with the rational posts by Tom Geiger, Art Anderson and charlie8575. It's a complex problem. One thing I might add is that market research done by individual companies is not likely to become publicly available. It is expensive and is usually considered a trade secret -- there would be nothing to gain from giving it away, especially when competitors might be able to use it to aid in competing against the company that paid for it.
On the other hand, many of Harry P's posts, especially the ones stating that building a model not being educational, don't seem worthy of one who is a moderator. I'll side with the trio mentioned above.
I've built plastic models, mostly of cars, since I was a little kid in the late '50s. I've had "how to" articles on them published since the '70s. My career since 1982 has been with die-cast toy and model manufacturers in the new products departments -- and often being involved with people formerly with the model kit manufacturers. I know, at work I'm part of the "dark side" since the majority of die-casts are already assembled, sometimes have fad trends in styling that traditionalists abhor, and on and on. Still, my hobby is building models. I can't predict the future of the hobby but it sure is interesting.
I have the luxury of living two miles from a huge brick-and-mortar full line hobby shop -- I hadn't even realized it existed when I moved here (east of Los Angeles) fifteen years ago. It seems to be going great. It stocks the common kits and items that one would expect, plus it carries all sorts of obscure items (weathering powder, for example), has a big RC track out back and is staffed with knowledgeable people. The store manufactures (or, at least, store brands them) hobby items, too. So between this store and the internet, just about anything I could want can be purchased -- and then re-shaped by me into my own vision in scale.
I can't imagine how things could be any better.