Please don't cross into personal attack on HN. You can make your substantive points without that.

https://news.ycombinator.com/newsguidelines.html

The fact that these exist does not mean that they're immune from legal challenge. If the original creators wanted to sue, there are all kinds of claims that would have a decent shot in court (e.g. trademark, trade dress, design patents) besides "you copied our copyrighted source code." The clones exist more because people are being cool about it, and because there's not a strong economic incentive to challenge them. Those things can change at any time.

I think I'm even older than you, because I remember what Nintendo did to the Great Giana Sisters.

Good luck making an open source Pokemon game clone and see how it goes