I guess in real life, the reason (for leaving out the important variables) is a combination of:
ignorance
technical difficulties with measuring something
people not caring deeply (just doing their job in the easiest possible way)
legal reasons (it is not allowed to measure something)
To use an example of software developers being evaluated on how many lines of code they write:
the manager has often zero programming skills, they couldn’t tell good code from bad even if they tried, so they try to measure something they can understand
what is a “good code” actually? ask five programmers in your team, you will get five different opinions
the manager doesn’t really care about the quality of code, just tries to make their boss happy by making some kind of report
it would be really bad if it turned out that your diversity hire actually sucks at coding, so this way you at least provide them a chance to get good results on paper
I guess in real life, the reason (for leaving out the important variables) is a combination of:
ignorance
technical difficulties with measuring something
people not caring deeply (just doing their job in the easiest possible way)
legal reasons (it is not allowed to measure something)
To use an example of software developers being evaluated on how many lines of code they write:
the manager has often zero programming skills, they couldn’t tell good code from bad even if they tried, so they try to measure something they can understand
what is a “good code” actually? ask five programmers in your team, you will get five different opinions
the manager doesn’t really care about the quality of code, just tries to make their boss happy by making some kind of report
it would be really bad if it turned out that your diversity hire actually sucks at coding, so this way you at least provide them a chance to get good results on paper