I would imagine buyer's remorse is more likely than anything to do with the device itself. The average person isn't as anal retentive about screen perfection as some of the folks that populate sites like this one........
Here are two posts from another thread. These two people alone created 11 open box items.
"In the past two days, i went through 10 ipads. most had tint issues where one side of the keyboard looked yellow while the other side was gray"
"I've also returned two iPad 3s - both with bad blue/pink random tints"