Well, it's not common sense because it isn't necessarily a consistent position. Just because you don't like people taking your code and bundling it into a proprietary product doesn't mean you're necessarily also okay with using the legal system to enforce that preference.
For example, I release my code into the public domain to the extent possible. But I am also very strongly opposed to plagiarism. Yet putting code into the public domain means people can legally plagiarize my work.
For example, I release my code into the public domain to the extent possible. But I am also very strongly opposed to plagiarism. Yet putting code into the public domain means people can legally plagiarize my work.