Oh, cool topic! I like hearing what everyone has to say.
For me, it's in my blood. My whole entire family quilts- my great-grandma taught my mom and my aunt, and my grandma (who was her DIL) taught me. My sister and my cousins all quilt on some level so I think we just absorbed it while we were playing under the quilt frame while the grownups were tying off quilts.
Another reason is that I just adore fabric- the feel of it, the colors, how it looks in stacks. (What do you suppose it tastes like...?) I guess if I just bought it with no reason my husband would have me committed so I say it's for my quilts. LOL!
I think that quilting is the perfect marriage of creativity and usefulness.