I've already answered in this thread but I keep thinking on the subject because there are so many arguments to make and so many nuances to it. Some might disagree with that and say that, no, it's always wrong, but I just can't agree.
I think part of the problem when discussing this topic is that we try to apply blanket arguments or comparisons that don't quite fit to the same context as video games. I feel like they exist in a kind of grey area between physical products and stories/ concepts.
Imagine a company that specialises in making, say, vases. They're a high-end brand and they're known for their particular styles. Imagine they stop making a particular model of vase, that vase ceases to exist in the market. Others can copy, but the style and colour won't be exactly the same, and the quality probably won't match either. The exact product is gone, both materially and in the perception of its buyers.
This isn't the same with a video game. The publisher might stop selling the disk or cartridge that it came on or stop offering the download, but the product is still out there. It's obtainable by people who still want it, but they're forbidden from obtaining it.
You could say it's their intellectual property, what if they want to offer its resale in the future? That's a fair point, but it's hypothetical. This is especially shaky ground with publishers like Nintendo, who have a beloved back catalogue they've never re-offered in their original forms, like the GBA Pokemon games. To buy and play these legitimately is as inconsequential to Nintendo as piracy, since you cannot give them money for these games. With the remakes, it's wholly arguable that they'll never offer these games in their original forms. NSO+ is there, the platform is ready, but they still aren't offering them.
There's the moral argument to pirating these games: 'Just because you want something, doesn't mean you can take it illegally'. But is illegality the be-all-end-all of whether you 'should' do something? Is a child who shoplifts a chocolate bar as morally bankrupt as somebody who robs a house? What about an adult who does the same? What about if they steal medicine for their child? What if a child does it for their sibling?
The morality of theft as a necessity shifts with every detail. Stealing basic needs like food and medicine isn't comparable to pirating a video game, true, but that's because of the importance of those items contrasted with the importance of whoever is selling them to see their profit. But with discontinued games, we're talking about a merchant who not only cannot profit from their product, but has openly signalled that—at least for the time being—they're uninterested in profiting from said product. So can you decry piracy of that product when said 'piracy' amounts to taking something ostensibly abandoned by its seller so that it can be enjoyed past the point of its arbitrarily designated 'salesworthy' period?
'The law' forbids theft, but 'the law', depending on which sides of various lines in the sand you stand, also forbids protesting, abortion, criticism of government, or even something like dancing. The law is relative, therefore any morality ascribed to and dependent upon law must also be relative.
It's not a black and white situation.
Inb4 I ain't reading all that.