Albatross
It is not just the chap who does the sim ride who has the ability to say 'No' to you joining. From the whole plethora of people who you meet during your time at interview, it only takes one to 'blackball' you.
Usually, of the two guys who sit with you in the sim, at least one of them will have met you for some prolonged period during the interview process and will have an idea of your qualities, or lack of them...........
You get looked at twice in the Sim during the DEC interviews so a better judgement of what sort of person you are can be made.
And this becomes the point where all of us become discriminatory.......the question that need an answer is: 'Would I really want to fly with this guy, and would I be prepared to let ALL of our crew members fly with him? Will he be good for the company?'
If the answer to any of these is NO then they have to, for many obvious reasons, say 'Sorry, no job for you.'
The proof of the decision is the reaction of the indivual concerned.
You quote the lack of ethnic diversity, the white majority, and biased (or discriminatory) practises in the recruiting process. I offer a suggestion that maybe, just maybe, the recruitment department got it right this time.
No on likes to be told that they don't make the grade, whatever their race colour or creed. How you take it shows your personality for what it really is.
Lecture over and awaiting a broadside.