Speak for yourself.
I love blue eyes. But I am not averse to any others!
As far as dilation, the point was one can SEE if the pupil is changing. They look for change, don’t just stupidly assume the whole iris is the pupil.
I doubt that the instinct is finely honed enough to detect slight changes in a pupil's dilation, but ignore the illusion that the entire iris is one giant pupil.
It seems like a weak thesis.