After all, what are they going to buy instead with their refund? There would have to be a card performing better for the same price in order to make a trade make sense and even then they'll be spending time ripping apart their pc's and travelling back-and-forth to stores or sending back units to online shops. Lots of trouble for little gain.
I'm happy that anandtech took the time to point out the issue but it isn't nearly as bad as it looks from a technical point of view, the discrepancy is only a major one if you notice it in an application that you run and in that case it might be worth the trouble but if you're happy then I don't see the point.
Imagine you bought a car that was advertised as having 7 cylinders and it turns out that you only have 6. That would be the nightmare of every car company but in the end the number of cylinders is less important than whether or not the car performs for its assigned duty or not.