Because if we get the product at a secondary market, that means that it has been sold and out of the store. When companies make exclusives, the only thing that matter is to sell them all.
Here's the deal though - how many items would they have sold if the item was not exclusive? Would you sell more items if you were in all the Wal-Marts vs. multiple retail chains? I don't think so. There are parts of the country where Targets, TRU's, and even Wal-Marts are non existent. Granted, they can jack up the margin for exclusives because they put a pretty case around them and make it sound rare, and I'm sure the retailers like it, but its ridiculously hard to get some of these items without help. I don't know about you, but I get awfully frutrated having to pay 2x retail because I don't have any WM's nearby.
Here's what they OUGHT to do...only offer excluisves if there's a way for everyone to access them. Go ahead and sell it at Wal-Mart as long as you can buy it at WM.com or starwarsshop.com. Then you can still charge $15 for a basic figure, but at least everyone has a shot at it. Or, just offer the exclusive stuff on line. If big box retailers want something exclusive, let them have it exclusively for a month, then make it available elsewhere. There are still tons of people who will flock to retailer x because they can get the item there first.
I just don't think its worth the possibility of chasing away potential buyers. If you lose ten hardcore collectors for every exclusive you offer, what is the total opportunity cost of those ten collectors, who might have continued collecting for another 10-20 years? Seems like a good way to ruin a franchise vs. something that would bring new people in.