This is a fascinating thread. Many of the reasons others have given for quilting apply to me as well, but an important one for me is the desire not only to be creative but to produce something functional. I have watched so many people accumulate too much "stuff" over the years (and then regret living in a cluttered and burdensome environment) that I cannot in good conscience make more "stuff" and give it to them. With quilts I am at least giving them something that can be used, and even if they do not swoon over my fabric or pattern choices, it will keep them warm on a cold winter's night. The usefulness component is vitally important to me.
And I love love love to be messing around with fabric...
Alison