Having personally seen the pink/green color cast on a total of 9 different iPads, 5 of which came from different stores/shipments, I feel there are far fewer "perfect" iPads than perfect ones out there in the wild, that people are aware of.
There are several factors here.
1. Most iPad owners are not on macrumors.
2. Macrumors members without a screen problem (noticed or unnoticed) are not participating in the discussions about screen problems.
That said, I feel that there are a LOT of defective pink/green screens out there, and that people either haven't noticed, can't see it, or don't care.
Case in point,
this post, whereby the poster shows the photo below and states "The backlight seems perfectly even on mine. The following pictures don't do it justice at all".
So far in the various threads, I've seen maybe 2 instances of a good looking screen, with photos. But I've read dozens of "my screen is perfect" posts.
I have a feeling some people are just not visually sensitive enough to see a poorly colored screen, as evidenced by the post and photo above.
So if you're gonna boast about your perfect screen, and call those who are seeing a problem crazy or OCD, how bout you put your money where your mouth is and show us a photo? If some of us are in fact OCD, some of you are, in fact, blind, and I just proved that.