"That's a bit of a paradox in the perception of charity. If you donate to charity, and then stop, you get far more shit thrown at you than someone who never donated to begin with."
It doesn't seem like Elon is donating because he is extremely concerned about something. It always seems to have the aire of a PR stunt and a way to build himself up as a techno super hero.
Elon also has a lack of grace. He could have come in with a set number of Starlink terminals and accounts and made it clear that there won't be more hardware so look after what you get. Instead he created the expectation that he'd replace failed and damaged units and manage the accounts so captured hardware would be deactivated. Then one day, he says it's all far too expensive and he's cutting them off and goes on to suggest that the US or some other entity take up the costs of supporting everything he's been doing to date and send him checks. Now that people have become accustomed to relying on the gear, it's harder to disengage especially for the military.
I agree that too many people are critical that wealthy people don't give enough or should keep giving to a charity after they have already endowed them with a bundle of money. I can easily see that there are more hands out than packets of banknotes to put in them. Charities need to make the most of what they are given and not get too used to a limited number of generous benefactors. If the charity does good work and doesn't squander money, they can use the donation of one entity to chivy a couple more to donate to them too. If they are paying their directors fat salaries and fly them around on private jets, the first big donor may elect to cut them off and while not criticizing them in public, will let other philanthropists know that there may be better places to donate money. I'm sure Bill Gates would love to be known as the person that sponsored a group's success in coming up with a cancer cure so Mr Bill is going to want to donate money to the groups that seem to have the best hope of achieving their goals.
Part of Elon's problem is his gross lack of social skills and king sized braggadocio. He's not a clear speaker and fails to consider the political and social impacts of what he says and does. The term "bow out gracefully" has no meaning for him. He could tell a little white lie that due to the chip shortage and needing to keep Starlink a going concern, he has to pull back on replacing hardware but he can keep the accounts going. As time goes by, those accounts will drop off as hardware fails, gets damaged and captured. The whole thing fades into the background without creating a bunch of negative publicity and he can use his support down the road without people instantly remembering that he tried to pull out and stick some government with the bill for his "charity".