How interesting. I've only been quilting on and off for about 2 years. I use the patterns in books, mostly so that I can 'see' what I'll end up with, and get the yardages. But often I'll find myself handling a fabric, then I spot another fabric, then I think.... let's take these to the sewing machine and make some HST... then before you know it, i've got a simple pieced (like ohio stars) wall hanging top done. I have bought kits for some big projects, particularly applique...
So I guess I use them, sometimes. I find the books helpful in learning 'what' goes with what. Just yesterday, I discovered that pink and chocolatte brown actually go together. I was startled. I'd never think of that color combo on my own...