I'm not sure getting a globally yellowish screen is that common nowadays or too much of an issue, as it can be calibrated, at least to an extent.
The real issue is that Apple is completely unable to build retina displays to the uniformity standards of their own TFT screens.
The RMBP 13" I now use is the fifth one (I exchanged it four times) and I decided to keep it as it isn't as rubbish as the other ones.
There are three common issues :
1) black point luminance unevenness. Also known, sometimes, as backlight bleeding. This is not related to IPS glow.
2) white point luminance unevenness.
3) colour balance unevenness. That's IMHO the worst of the lot. Of the five RMBP I got, three had totally unacceptable colour heterogeneity, going from sickly yellow in one corner to magenta in another one. It was obvious, and I never ever had an issue to demonstrate the existence of a problem to Apple's staff. It's that bad. The other two were begrudginly acceptable in that regard (but the first had a massive issue with luminance heterogeneity).
The main point of contention is that when one buys the MBA, nobody expects to be able to to any modicum of photo / graphics editing on that display, as the technology itself is problematic, but that, at least in theory, RMBP displays should be good enough for a limited number of editing uses, and yet, in practice, because of Apple's inability to rein in their wide manufacturing tolerances, only a very small subset of these displays is actually any good for those uses.