I think improvisational quilts serve many purposes. I'm taking a class with Kathy Schmidt in a few weeks on just that subject. While I appreciate traditional, symmetrical quilts, I also appreciate more free-spirited creations.
Beyond that, I think that sort of quilting can be good for your creativity. Stepping outside your box can tap into another part of your brain, and while you may not get hooked on something "wonky", it may have a positive effect on the traditional quilts you do create. Just like "muscle memory" is good for doing FMQ because the doodles and designs stay with you, exercising a new part of your brain can get things going in other ways.
I think that's one reason the Quilting Board is so successful. There are so many kinds of quilters here; there's no way you can be expected to love all of them, but being exposed to so many different creations can only be helpful.
Quilt on!