This is my point. Until I started reading this thread and trying the test, I thought my iPad 3 was a perfectly working device. Of course, it failed the image retention test within a minute, and my rMini LTE shows some retention after 3 minutes of 100% brightness. More importantly, if I look at the test with my eyes for more than 30 seconds, I can see the test pattern ghosted in my vision whenever I look away. So is there a problem? I guess so, but in real world usage, I'd say it will take years before it can really affect day-to-day usage, and even then I'm not sure.
To be upset with it would assume that the device will be used indefinitely. While I would love that to be a common expectation for everything I buy, I think we all know that neither Apple nor should we expect that type of life expectancy. If you can get 3 iOS refreshes on a device before it becomes slow and buggy is probably typical, and I would think 3 - 4 years of use would warrant the price tag of an iPad with AppleCare, LTE, and sufficient internal space (32GB or higher). Of course you can use it longer than that, but to expect it to be operating perfectly without replacement of faulty or broken parts, like a screen, is probably unrealistic, or perhaps a bit juvenile. Bring on the Ralph Nader haters. Or better yet, the Steve Would Have Never Let This Happen naysayers.