As someone who had a great iPad 1 and 2 on the very first try, and has been through 7 new iPads of my own and has personally inspected nearly 50 others, I feel pretty comfortable in saying that there is something up with the screens of the new iPad, period. I've handled nearly 50 of them. All but 1 or 2 showed some issue. People who indicate their iPad is problem free have likely handled 1 or 2. You do the math.
Add to that the increasing number accounts of multiple returns, and compare that to the accounts of returns for the iPad 1 or 2. Back then, if you got a wonky one, the wonkiness was gone by replacement 1 or 2.
Is everyone sensitive to, or do most care about, color shifts/tints/unevenness? Clearly not, or as you've said, the mass returns would trigger media attention. (Though history shows that mainstream tech stories regarding bugs and defects are often born on discussion boards...remember the dude who got a new iPhone with Chinese factory pictures already on it? That went viral straight to the nightly news. Posted first on macrumors.)
But insensitivity or lack of caring doesn't mean these iPads don't all have some issue with the displays, beyond the typical shortcomings of LCDs. It could be the manufacturing process. It could be lack of QC. It could be an issue inherent in the technology. I suspect it's a combination of all 3.
Based on my past experience, an iPad with a problematic screen was the exception, not the rule. This time around, the problem free iPad seems to be the exception. To my eyes. And my eyes are no more sensitive than they were for the iPad 1 or 2.