as if the two were mutually exclusive

Because they are. If you're prioritizing one metric of judgement, you're inherently putting at least some metrics below it. And unless you're of the stance that there's a big stack of 100% identical in every way other than diversity qualities, those people are all going to have different levels of actually relevant qualifications.

If you're making selections based on diversity, you're fundamentally not focusing on hiring the best of the best. And for safety critical positions like pilots, I would much rather have the focus be 100% on quality.