I may or may not speak for others when I say that continuing to keep exchanging iPads partly stems from a disbelief that Apple would release a product so inherently compromised. To those that see, notice, and care about this issue, it's quite glaring and rather disheartening.
Given that the iPad is basically a big fat screen, that its first and foremost purpose is to deliver content on that screen, that it's one of the most, if not the most expensive tablets you can buy, the screen should great. Does that mean there can be zero flawed screens? Of course not. But there also can't be zero flawless screens either. So far, based on what I've seen and others have reported, flawed screens seem to be the rule, not the exception. I've only seen one apparently flawless screen, and that was in showroom lighting where things are often not as they seem.
Retina alone is not enough. Color rendition and evenness of lighting and color are equally important ingredients of a great screen. A failure of any one of those elements compromises the others' ability to deliver a great experience.
But surely it can't be that Apple, perfectionists that they are, (the very same company who hasn't released iPad Minis with retina screens yet because of reportedly imperceptible panel flaws that don't meet their "exacting" standards) could possibly have created 10 million iPad Airs with half yellow screens. Surely it's just some crazy coincidence, that a few dozen random people are getting defective screens, and have seen defective screens in stores everywhere.
If it's truly impossible that Apple could release an inherently flawed display, that no one noticed anywhere along the production or inspection line, then there must be millions of flawless ones out there.
And that is why people keep looking for one.