If you can't see how such a situation is fundamentally different to sharing, for curiosity or utility, software for long-dead platforms published by long-dead software companies, then boring isn't the only thing you are.
Say your work was a cure for cancer, but you suddenly came to the conclusion that people with cancer don't deserve to be cured. It would obviously (still) be immoral for someone to take your work and call it their own, but would it be immoral to make and sell bottles with red labels that said "SCOTT BARET'S MAGIC CURE FOR CANCER"?