I know the fundamental answer...one or both sides (the Mountain and the businesses in Stowe) did not expect the promotion to be beneficial to them this year.
As a customer of both, I am very disappointed. Were the Stowe shops participating I would have snapped up a new pair of skis or jacket for my wife, or perhaps a new pair of boots for myself. Instead I had to comb through the list of participating stores in Burlington to find one that sells something that we actually need AND is expensive enough that we won't need to buy 50 different things to get the maximum benefit.
I hope that in the future the two sides will find it mutually beneficial for Stowe retailers to participate in this promotion again.