Many people make statements that a given group of people has things statistically worse in some way than others, and argue that it shows the said group is "systemically" disadvantaged. The core logical problem is that the lines used to demarcate the groups are arbitrary.

Consider that if it's fair to say "people with dark skin have things worse statistically, therefore they're oppressed and deserve affirmative action, what stops me from arguing, "people with 6-letter screen names beginning with Y have things bad statistically, and therefore deserve affirmative action"?

The only answer is: because the lines used to justify such treatment are entirely arbitrary, and picked out by people with political motivations in order to win votes rather than in the interests of stopping actual discrimination (like affirmative action).