Your example is a case of discrimination, but the economic rationale is unquestionable. There is a tremendous upfront cost for new employees, who are not valuable contributors for some lengthy ramp up period and furthermore accrue experience over the course of employment. So the lifetime value curve for any given employee is typically skewed left.

I think I'm just being difficult.

My point was that when you call something a double standard, you're arguing two things of equal value have been judged differently under the same standard. But by acknowledging they've been judged differently, you're acknowledging that there is a judgement, a standard, that applies the same to both, and produces the results you object to. What you really object to is the fairness of the qualities checked by the standard.

Since the outcome of calling things that, vs calling them a double standard is the same, I think most people already know and have no trouble with this. My protests were worthless.

It could gain value if there were certain whitelisted judgable aspects (like expected value), and judgements that aren't based on things from the whitelist are considered outside the scope of a standard. Then, calling the standard unfair and calling it a double standard would have a different meaning (if only in some contrived way, since any aspect is just an argument away from the whitelist)