While that may be true, remember that the sim is necessarily a dramatically cut down version of reality. They can not simulate weather or lighting effects to the depth you see out the window.
Specifically, when it comes to rainbows, the problem they have is the simulation of “attenuation” – dropping signal strength – due to water density, air pollution, etc. For example, they can’t simulate fog – the just put a cloud at ground level.
So the rainbow effect is not very realistic, because the weather has these layers of clouds and no degradation of light signal due to distance or density effects. Just thing of all the times you have seen a rainbow, and I’ll bet it’s typically very faint, or nearly always just a short segment of the possible full circle, or you didn’t even notice it until someone else pointed it out. You also had to be at the perfect distance and the perfect angle for the refracted rays to reach your eyes.
Like I said – two schools of thought. I want pretty even if it’s unrealistic, or, I’m a grouchy old fossil – you can keep your pretty – all I want is what I perceive to be realistic.
Nobody is going to happy unless you give them the whole spectrum and a way to control it. And this – hopefully – is on Asobo’s very deep backlog. You can’t enjoy pretty or realistic until they fix the flight models and AP logic.