The whole point of these highly permissive licenses is that we don't want to constrain independent hackers, or put people in a position where they are unsure if

The whole point of these highly permissive licenses is that we don't want to constrain independent hackers, or put people in a position where they are unsure if their fork might expose them to liability. It is undoubtedly discourteous of AWS to release an OSS fork as a new feature without crediting the original author. It is not the end of the world. It is not a reason to go and change your licenses to make things more difficult for the other 95% of developers. But it is a reason to say "some people at AWS are just dang ol' jerks."