reminds me of my own software I created and was selling online 20 years ago.
I lost the source code but people still wanted to buy it. So I sold it for few years (shareware). I had a serial key generator for windows but it was annoying to do this manually.. I wanted to extract the key generation algo so it can be generated automatically after payment.
I also tried many disassembly tools like ghidra, but without luck. I decided to stop selling / supporting the software.
Nowadays, I still get the occasional mail from people asking where they can buy it, or of there are some updates.
It's pretty clear that the program has utility, otherwise people wouldn't ask.
Giving it to computer cracking groups as a real world program that they can use as a teaching tool has some value too.
I mean, if you you're not willing to take the money for the program anymore, then you have little to lose with this.
(Unless there's some other reason not to do it, brand harm for example, or third-party code that's licensed and that you do not have permission to subgrant reverse engineering work)
