Makes sense to me. Being able to show a pass from your local flatland bump for a discount is not the aim/goal of the offer. It is to get occasional guests away from nearby competitors to try Magic and hopefully come back for more.
But why would you limit your market? I think its very clever marketing and I like the idea. I get a Jay comp with my Camelback pass and I've used it. Yes discounted tickets can and do drive me to a mountain. Most pass holders where ever are the hard cores who you want to come and support the mountain.