Another thing you need to factor in are the amount of UFO's most quilters have at any given time. First the quilter needs to finish these before they can even think about starting a scrap quilt. I now have a large black refuge bag full of different size scraps.
I know I could get quite a few improvisational quilt patterns going too which is a great way to get the creative juices flowing although I have been known to spend a few hours on an improv piece only to look at it and laugh and ask what I was thinking! I don't mind doing these things though even if they are a waste of time because sometimes if you are lucky they can become something wonderful.