The consensus on that list is that License Zero violates certain tenets of the Open Source principles, and as such software released under a License Zero license is not open source software. By extension, this means that getting to work full time on License Zero software means that you’re not working full time on open source software.
I don't care about other people's definitions of the term open source. To me, software is open if I can read the source, modify the source, and redistribute modified or unmodified copies. If I have to pay to use it when creating proprietary software, or within a commercial context, then so be it. It makes sense that the people most closely deriving financial benefit from a piece of software should be the ones to fund its continued development and maintenance.
The FSF's concept of four freedoms always appealed to me, but the problem is that freedom 0 allows people to take away the freedom of others, because it allows the creation of proprietary software. The Parity Public License doesn't have that hypocrisy. https://www.gnu.org/philosophy/free-sw.en.html
The consensus on that list is that License Zero violates certain tenets of the Open Source principles, and as such software released under a License Zero license is not open source software. By extension, this means that getting to work full time on License Zero software means that you’re not working full time on open source software.