First off, you will never see "counterfeit" sneakers donated to anyone. Why? Because those that they are counterfeiting aren't making a profit, tax write-off or any other "incentive" for them to want to donate them. Additionally, if they are donated, then that will drive down their $150/pair prices (heaven forbid).
Furthermore, this also show how materialistic we are. Here we have a shoe that is probably no different than the "real" thing, yet they are being destroyed because they weren't made by some 8 year old kid in a Nike factory, but were made by an 8 year old kid in some other factory. With all those shoes, they could probably put several pairs on every kid that works in their factories.