IMO it's only fine as long as it respects the user's choice and doesn't keep on asking. If I choose to not donate, do not nag me about it the next year either. If I choose to donate, do not remind me to do it again. I will do it myself if I decide to.

Perhaps it's cultural - where I live repeatedly asking for money is highly frowned upon and only lowers the reputation of the non-profit doing it. The non-profits who only ask once are much more likely to receive multiple donations from the same person.