I think problem goes deeper, with the modern mindset of a lot of people nowadays, we don't want to wait/work/earn anything. We want to whip out the plastic, charge it, and play. Instant gratification.
I personally don't see the point in the "pre builts" other than as a conversation for someone who wants a one off piece to use as a decoration.
I myself hate the mentally that has made us so dependent on a disposable life style, but that aside. I just finished building a loft bed for my son, with a desk and book case underneath, plan on building a bed for my wife and I, that will double up as storage space (although she has made it quite clear what the athstetics of it will be :) and I am now in the process of building a knock down able modeling desk/work are out of the common wood scraps in the garage to make room for that project. I could of bought all these items, for probably less than the cost of building them myway, and had it over and done with. The one thing that would be missing though, is the personal satisfaction that all those projects bring.
Much like our scale modeling, people may not understand the desire to work in miniature, risking thumbs and other digits against surgically sharp blades. But it is the escape, and the sense of completion and satisfaction that comes afterwards. And that dogged determination not to be beat by a box of styrene.
I hope to install this same bit of ethic in my son, even if he doesn't develope the same intrest in scale modeling, I can only hope he develops the same sense of personal satisfaction from working with his hands, and actually doing for himself.