If someone incidentally acquires a license to a product, quietly removes the product from the market, makes no announcement about some moral justification or about a new version coming out, and makes no movement for several years, I consider it acceptable to label that product "abandonware" and pirate it. If the license holder later comes out with a new version of the product, the right thing to do would probably be to buy it, if the pricing is reasonable. If they later come out and say "actually this product is (somehow, don't ask me how) unethical", I'll consider deleting it.

There's no way to get these things perfectly, but I also want to add that I don't consider it ethical to pirate things made by indie creators, or books (with the exception of textbooks), and that I'm probably unusually prone to outright buying new books or indie games or legal first-party mp3s of music, because I consider it a bit of a duty to support media that I appreciate or want to see more of.

At the end of the day, I think I do more to contribute to creators I appreciate than the average consumer, but I don't lose much sleep when I literally cannot access an old classic at a reasonable price and I flip a coin between "stealing it" or just doing something else. Nobody was going to get my money either way, and I only have so much patience and willingness to try to do things "the right way" before I decide they've made it unreasonably expensive or complicated on purpose and screw 'em.