I don't think "scalping" is the right word. If someone was crazy enough to dump a truckload of money and buy all the Kickstarter pledges then it might be scalping, but 1. That didn't happen. 2. The project owners would love it! 2. It's not a successful business model for scalpers.
If someone happened to pledge and now wants to sell their pledge for more than they bought it for, it's not any of our problems. The buyer inherits not only the risk of the original Kickstarter project, but also the risk associated with a grey market transaction.