I'm sure they were technically brilliant, but it really sounds like it was weeding out people who would not be compliant. It's a small jump from that to realise

I'm sure they were technically brilliant, but it really sounds like it was weeding out people who would not be compliant. It's a small jump from that to realise it's most likely weeding out people who have 'egos' that might make them object to morally dubious orders. Arbitrary requirements (like polygraphs which are literally bunk) are the most classic way to select for compliant people.