As others have said, walking is a symptom of the demand >>>> supply. While a surcharge could be a way to reduce demand, as others have said, it's not likely to make a difference in overall demand. And restrictions and surcharges devalue DVC overall.
Personally, I have walked, and will walk again if I have to. But I also have been on at 8am sharp on the days I'm booking at 11 months, and gotten the last room (BLT standard - not as much pressure as AKV value and concierge), and to anyone on at 8:01am it probably looked like it was a walker. Surcharges will still do nothing to make value of concierge rooms more available. And the # of posters saying they are picking up rooms in the wake of the walkers also says something - if you don't get the room at 8am at 11 mos, keep checking. People cancel and change dates all the time, so you can use your wait lists and consider other options. I've had to book a LV at my home resort because standard wasn't available. First world problems.