The culture is different. The most noticeable thing is of course simply size. FreeBSD is by far the largest of the BSDs, but it is a much smaller community than Linux. That means that it is easier to get involved, easier to follow what is going on - eg look at the commit log[1] - you can follow it pretty well, vs the Linux commits where each is a large merge of a nested set of commits[2].
Sometimes small size means things can change faster, eg NetBSD has had 64 bit time_t since 2012, while 32 bit Linux still has no roadmap to fix this (the BSDs are also have a different compatibility model). Other times it of course means that less is done and things take longer. You will often hear people say the BSDs are better designed, as perhaps prioritising limited resources leads to more design, or maybe there are just fewer people who need to solve a problem fast but not so well.
Including (some) userspace means that the tools are less bloated than the GNU ones which were designed pre Linux as portable tools, before the Gnu project had a kernel - remember GNU was the cathedral in the cathedral and the bazaar.
Sometimes small size means things can change faster, eg NetBSD has had 64 bit time_t since 2012, while 32 bit Linux still has no roadmap to fix this (the BSDs are also have a different compatibility model). Other times it of course means that less is done and things take longer. You will often hear people say the BSDs are better designed, as perhaps prioritising limited resources leads to more design, or maybe there are just fewer people who need to solve a problem fast but not so well.
Including (some) userspace means that the tools are less bloated than the GNU ones which were designed pre Linux as portable tools, before the Gnu project had a kernel - remember GNU was the cathedral in the cathedral and the bazaar.
[1] https://github.com/freebsd/freebsd/commits/master
[2] https://github.com/torvalds/linux/commits/master