Look at Mac OS. That's what happens when freedoms don't have to be honoured. Corporations have spent a lot of effort trying to work around the GPL, whether it was via network services or something else.
If everyone had gone down the BSD route we would have been there, just a lot quicker. This is why I would never licence any of my work as anything other than GPL or AGPL (dual so that people can pay to avoid GPL, but they still contribute financially).
This is all a team effort to make the world a better place and BSD is too idealistic.
But that's not relevant to the parent's point, which is "If all open source, such as Linux, was BSD licensed, then only proprietary unixes would be common", which I happen to agree with.
Linux would have been further behind because all the proprietary unixes could take the best parts, without giving back (like Apple did/does with BSD), and all those thousands of full-time employees working on Linux would have created value for the shareholders of their employers, not value for the Linux users (like they currently do now).
There was a lot of Unix already, and Linux ate it's lunch by being a simple recompile away.
MacOS does a lot to try and hide that it's a Unix.
> There is a ton of cross pollination between mac and Linux software
Do we have any good examples, because Apple spends a lot of effort breaking cross platform compatibility?
> at least on the command line.
There is a lot of Linux command line software ported to MacOS, but I can't think of any good examples for the other way around.
