The people who are buying and returning/exchanging multiple iPads all have one thing in common. They want a freaking iPad Air. Getting an acceptable one, for some, is a labor of love.
They don't want to skip this generation, as so many have suggested. They will not accept "maybe the iPad isn't for you" as so many have suggested. They don't want a Nexus, or a Galaxy, or a Honhai SuperTablet 9000, as so many have suggested. Maybe they depend on the iPad for their livelihood. Maybe they have $1000 invested in apps and accessories. Maybe they just want a freaking iPad Air.
Regardless of why they want or need an iPad Air, they want one with a clean, evenly lit and colored screen, like the ones Apple advertises that they manufacture and sell. It should be noted that Apple does not advertise 1/2 yellow iPads.
If a 1/2 yellow screen doesn't bother you, or more likely, if you can't see it, GREAT! You are blessed! The people who keep getting iPad after iPad with 1/2 tinted screens are cursed....either by bad luck, or by a heightened awareness of color.
People with a heightened awareness of color are no different than people with acute hearing, sense of taste, etc. One man's over salted steak, tossed in the trash, is someone else's perfectly cooked Costanza dumpster feast. To some, a 1/2 yellow screen is like scratching a chalkboard with fingernails growing from their eyeballs. To others, it's the most perfect display ever made.
As I type this on my 4th Air, I have just paused, because I was distracted by the fact that as I type, as the sentences get longer, the background I am typing on shifts from yellow to blue. Just like the last 3 Airs I had. And so, like the 3 before it, this one will be returned.
Will I get another one? Maybe. Will I return it? I hope not. This is not fun for anyone. But like others, I really want an Air. It's a great device, if you can find one with that one teensy tiny feature that happens to be 99% of the selling point...a beautiful screen.
Of course, telling someone you think they should return their Air because YOU think it looks defective is dumb. But telling someone they should keep one THEY think looks defective is no less dumb, and arguably more obnoxious.
Who do people think they are to tell anyone else what to do with a $600 device that doesn't meet their standards, and doesn't do what Apple demonstrates that it does, in their demos, print ads, and commercials...which is to reproduce imagery of all kinds on a clean, evenly colored, and evenly lit screen?
Who is anyone to say that seeking out a product that does what it says on the tin is abusing the company making it? If this problem isn't widespread, as people insist it's not, then we are talking about an extremely low percentage of people making multiple returns. Apple factored those people into the equation long ago.
Given that the same screen issues come up year after year, in device after device, Apple clearly doesn't think it warrants much serious attention. The return rate is likely very low. It's FAR cheaper to keep giving the sticklers new iPads than it is to retool/retrain an entire network of factories to make sure the screens aren't half yellow, especially when most people can't even see it.