You could similarly say that Apache did the hard work with Lucene, then Elastic came and took it. Except, of course, if you think that simply hosting is not worth any money, but then Elastics own paid offering is void as well.

I really don't fault Elastic for disliking the situation; someone making billions with you work while you're still counting coins sucks. But they reached their size due to OpenSource and AWS, so painting them as the profitless victim really does not show the whole picture. And their handling of the situation so far was horrible; they've even gone so far as to embed code in their client libraries so that they don't work with Amazons offering.

So yes, in conclusion, Amazon really has the moral high ground here.