Operationalizing and validating concepts and measures is genuinely difficult. There's always a question of whether the concept itself is real, if the test is really measuring it, and if anything can be learned from precisely measuring it.

Personally, I think this tracks with how reified the concept is in a particular society. No one would think twice at the validity of a gender test, some may question the validity or intelligence tests, and many may question grit tests. The almost instinctual reaction towards tests says more about someone's degree of social internalization than it does about the test, though of course it doesn't feel this way to the person being asked - see reification above.