He has given up nothing. Free software is freedom, and don't forget that 99% of the time people have the freedom to IGNORE whatever you publish and use something else.
You can have your closed-down code base where nobody knows your software, and you're just another hacker. You open source it, get users, and you're suddenly a software publisher; all it takes is for one university or corporation to contact you for help and you're free to ask for compensation. If your software was locked down, you wouldn't have had that lead to begin with.
I didn't mean "given up" in a bad way; I was raised on OSS and think it's a great concept. I favor the use of it, even in cases like this., simply because it's a better way of doing things.
However, the fact remains that going open source reduces one's ability to control one's work. Trademark protection means that you can't be out-competed by yourself.
You can have your closed-down code base where nobody knows your software, and you're just another hacker. You open source it, get users, and you're suddenly a software publisher; all it takes is for one university or corporation to contact you for help and you're free to ask for compensation. If your software was locked down, you wouldn't have had that lead to begin with.