Amazon closing AmazonSmile to focus its philanthropic giving to programs with greater impact

I think that the email doesn't actually support your title - they make no claim of counterfactual focus. It seems more to me like the mention of other programs they're already investing in is trying to signal "hey we're still good, even though we're shutting down this program". I suspect that the decision is probably primarily profit-driven in that running a whole nother version of their website which donates lots of little amounts to tiny charities is a large infrastructure cost.

My personal commentary: probably not much of a loss, but directionally sucks. No charity was receiving much money this way as far as I know, but was a nice way to feel a bit better about shopping on Amazon since you got to pick where their charitable giving went, and I'm sure it had some marginal impact for some charities. I'm also sure there's a backstory, like wanting to not be neutral on where the funds go because they leave it up to customers to choose from any registered charity, but that's not present in the announcement.