This, I think, is the key. The few projects I'm working on right now are not at the point where business logic would come into play, but all contributors are in agreement that they would support this model over all.
It allows the public to continue to use your work to collaborate and create better things, which is the point of open source, while allowing businesses (which should be able to afford to license a software product) to still pitch in and generate a profit. Both of these will attract talent and interest and allow collaborators to prosper.
This approach is as old as the hills. From RMS' Copyleft: Pragmatic Idealism:
> Many years ago, a friend of mine was asked to rerelease a copylefted program under noncopyleft terms, and he responded more or less like this:
>
> > "Sometimes I work on free software, and sometimes I work on proprietary software---but when I work on proprietary software, I expect to get paid."
>
> He was willing to share his work with a community that shares software, but saw no reason to give a handout to a business making products that would be off-limits to our community. His goal was different from mine, but he decided that the GNU GPL was useful for his goal too.
The approach is far more common in other kinds of licensed, creative work. Creative Commons' choice to standardized noncommercial license terms helped make commercial-noncommercial licensing familiar in photography, illustration, music, and so on.
The model has gone by a few names. Those researching should search on "selling exceptions" and "dual licensing", too.
Some of the times when people would repeat things RMS said about sustaining Free Software work by making money from consulting on the side, this seemed misleading.
I understand RMS was at times the beneficiary of people who were sympathetic to his mission. For example, students said at one point he was living in a university office that someone arranged to be allocated to him.
Personal sacrifices like this, towards his principles, were to RMS's credit, but the suggestion that one could just pick up consulting work on the side seemed misleading. RMS was one of the better programmers, and famous, and even he didn't seem to pull off that sustainability reliably.
RMS originally made money for FSF by selling copies of Emacs and other programs on tape. That was back when the first person to buy on physical media couldn't just slap on the Internet.
That's before my time, and I think some of the stuff I heard about was from when most people were getting GNU software via FTP, and later. (Though FSF sold paper books.)
It allows the public to continue to use your work to collaborate and create better things, which is the point of open source, while allowing businesses (which should be able to afford to license a software product) to still pitch in and generate a profit. Both of these will attract talent and interest and allow collaborators to prosper.