Why is everyone pitchforking that it's not enough? It's a library that is free for everyone, nearly every company on the web uses it somewhere. Almost none of them donate anything. Someone at AWS went through the effort to make this donation, I think that should only be encouraged.
If you give a mouse a cookie, he's going to ask for a glass of milk. They didn't have to donate at all. $5k is not an insignificant amount of money for most people.