To me, this BSD-versus-Linux thing revolves around the difference between a centralized model of development versus a decentralized one.
Linux is just a kernel, whereas each BSD is a whole distribution. Linux distros take their upstreams from thousands of different sources, whereas the BSD folks seem to want to maintain their own copies of everything. And they still seem to think CVS is a good idea for version control, though they do try to offer Subversion as an alternative for the radical young kids. While on the Linux side, look at the number of projects that have moved onto distributed VCSes like Git and Mercurialthe Linux kernel itself never used any centralized VCS.
This decentralized approach, not controlled from any single point, is why the Linux ecosystem has been able to move so much faster than the BSD ones. BSD had a thriving community back when Linux was still a snot-nosed little upstart that could very well have died in childhood; yet look at all the great things it has been able to go on to achieve, while the BSDs havent really moved much at all.