I enjoy kits for many reasons, although I also design my own quilts. Where I live, there are no LQSs, so if I can find a kitted pattern I really like with fabric I really like, then I'll buy it. It saves me time, gives me access to fabrics I may never otherwise see and provides me with everything I need in one fell swoop.
There are several ebay sellers who create very nice kits with precut fabric for log cabins or kaleidoscopes, for example. I've purchased them and had great fun making them. I would never have had the patience or the fabric necessary to cut a kaleidoscope myself.
I too often reuse a kit pattern, and have sometimes found that there is enough fabric left over to make a second, simpler quilt (with a little help from my stash), so that too is a plus.