I designed something, it wasn't software, though there was a very small amount of software in the final product and some iterations. I was advised to patent it, and could have.
The more I dug into it, the more I thought 'this will stifle innovation'. My design was good, but by going copyleft the design is so much improved over anything I could have done. People with power management skills have increased efficiency, others with coding expertise have reduced the parts count, still more have added redundancies to make it failsafe.
It is a commercial product for a multinational, and a few small scale producers, but many more hobbyists have built it themselves by going to Mouser/Digikey etc. With a BOM.
I published it anonymously and have never made a dollar from it. I couldn't be happier with that.