Originally Posted by Peckish

Because it's generally not done. Most quilters fall into one of 2 camps - you either like the quilting pattern showing on the back, or you don't so you use a busy print to hide the quilting.

I think your plan will work if you do as Sally suggests - make sure you tack or minimally stitch the 2 completed layers together. You don't want any bunching or poofing out after they're sewn together.