[burner831234]

I think the reason people suggest anonymity as a morally positive or superior action is because this isn't in trade. You've given it away (as noted above) without having your name in etched letters on a building, without a desire for notoriety and not in trade of previous or in fact continuous poor deeds. Consider for example the controversy around Bezos' donations.

It is very similar in fact to tithing instead of the practice of having your name called out in service in front of everyone so you can later trade on that donation for social standing.