I personally think egg donation is very, very likely to be motivated by the things you mention--a kind of altruism. You have something so precious. I think a lot of gamete donation has this element where the person is aware there is a deep need for something we have--and we are rarely in a position to benefit another person so much. That really is tempting. I think this altruistic element is also true in sperm donation.
I suspect that most people have some altruism but do need the financial incentive because of the difficulty.
People altruistically donate kidneys also and receive nothing.
I wouldn't ask for a background check like academic records. But if the person is choosing you as a donor because this is really important to them and you are proud of it, would you really get angry about it?
I guess I would not do this. But seriously, it would take me years to save up the money for a DE cycle. If that was so important to me, it would be hard not to want to make extra sure.
People lie in all areas of life so checking on a person who presents qualifications is not necessarily personal and saying YOU are a liar. It's just what is done when a person claims qualifications of some kind.