I had trouble parsing this. "People are okay with not being paid (for charitable effort). People dislike not being reimbursed (for charitable effort)."

Reimbursement seems a non-sequitur in the context of donating blood. Without an alternative market for blood, framing it as foregone reimbursement would be actively antagonistic on the part of the charitable recipient [within the culture in my area]. eg, "we could pay you, but you shouldn't want us to."

Unless you are referring to a situation, expressed below, like not reimbursing significant travel expenses for mr blackfan-anemia. It's not clear to me.

I think the situation is about travel expenses, as that's the major issue that the article brings up. It's not an issue for people with common blood types. Just donate anywhere. But for dealing with rare blood types, it might help if rare donors didn't have to pay their own air travel bills.

I am referring to eg. being reimbursed for travel expenses, or any other expenses which would not have been incurred by not donating. Being "made whole" on money you spent.