I personally experienced that just last week.
When I returned my iPad 2 last Thursday, the BestBuy employee & the GeekSquad guy
looked at me like I've just robbed a bank or some other heinous crime when I told them that I'm returning the iPad 2 because of backlight bleeding.
I definitely felt embarrassed, given the look on their faces. Not only that, they told me that that was the first time since that store carries iPad 2 units for sale that anyone has ever returned an iPad 2 due to backlight bleeding issues.
Worst of all was that although I pointed out the backlight bleeds to them, they both said that they couldn't see it at all & told me that such bleeding are the norm for all the iPad 2 units.
They
politely insisted that I would get the same backlight bleeding even if I open up all the rest of the iPad 2 units that they had in store that day.
They simply refused to let me make an exchange, but at least they let me returned it, which I am very grateful for.