It's one thing to steal algorithms but for interoperability to remain possible it is necessary for API to remain "fair use". I can't agree with you that this is a bad thing for them to copy Java SE interfaces.
Fair use makes sense to me when you're talking about the table of contents of a book. If I take the table of contents of a famous novel and write my own chapters, it makes sense to me that the owners of that book shouldn't be able to sue me. No one is going to read my book instead of Faulkner's. There's no equivalency there.
If I take an API (the table of contents equivalent of software), that's seems totally different, if not the opposite really: the interface is what matters, and the implementation is secondary. If you apply the analogy to a novel, it's as if I took the table of contents of a famous novel, write my own chapters, and it'll be equivalent to the famous novel. My chapters could be slightly "worse", but readers wouldn't necessarily notice a difference between my version or Faulkner's.
But that's kind-of the point IMO - if we take a free-market approach to this, copying (or sort of "standardizing" onto) an API allows for more innovation, since it's not a prohibitive up-front cost to switching the implementation. We don't copyright (or I guess patent, and I know they're different) the user interface of a fridge. Any fridge can have 2 doors and a slide-out freezer, but it's the actual implementation that would matter to a user - how energy-efficient it is, how cold it can get, extra conveniences (maybe akin to API extensions) like a water/ice dispenser that still can be "copied"/used by other fridges. And I'm sure that maybe those "interfaces" were patented originally, but it seems absurd now that they're so commonplace to restrict who can implement them.
I think the same applies for APIs. It's only taking away users from the original implementation if the new one is better.