I side with you. I’ve donated over a gallon of blood and blood products throughout the years. You’re helping someone. The reason they pay you is to incentivize coming and doing it. It’s painful for the donor, and it takes a while for your body to recover. The company doing so is (in my experience, anyway) a non-profit organization. They exist to help people. They do make money, but that’s because they have to pay their employees and donors, as you’ve mentioned.
No, it’s affirmative action. It specifically removes bias.