[mountainb]

Because the writers want to build support to expropriate that racial group. Just imagine if it was "mostly Jewish men and women" and it's easy to see. In this case the cofounders actually were both Jewish, so they are both racially white and ethnically Jewish. If they identified them by their ethnicity or religious identification in such a sentence, they'd get a call from the ADL. You can write or say anything you want about whites in the most incendiary Radio Rwanda type terms and keep your job while advancing your social standing in the United States.

[BlueTemplar]

It looks like race categories are unhelpful anyway. Ethnicity is helpful, and religion is the most important part of it. Just look at the ethnic conflicts between same-race ethnies like Muslim semites vs Jewish semites or Protestant whites vs Catholic whites (Irish, Latinos)...