Why do you use Linux instead of BSD? It's the same question.
Some potential reasons for using FreeBSD:
It's the same three firewalls forever, not a progression of different firewalls.
Old knowledge still works, for example, netstat is still the way to list socket connections and ifconfig is still the way to configure interfaces. I did some work with FreeBSD in 1999, and then nothing until 2004, and all the knowledge transferred, then in 2011 I changed jobs and skipped ahead several versions, and again all the knowledge transferred. But I kind of stopped using Linux heavily in 2013, and when I had to work on it at work in 2016, all the tools had changed, so I had to relearn (or just avoid the Linux part of my job, which I had the luxury of doing).
Official kernel support for ZFS.
Receive side scaling support is nice, if you need it; although I guess not a lot of people do.
Different positions on philisophical arguments like an integrated source repository with the kernel and the base userland software, or init systems.
The "old knowledge" thing is a huge one - I know there are reasons why Linux keeps changing which firewall manager you're supposed to use and now we do ip addr show instead of ifconfig eth0 but it is annoying to keep up.
I know Linus has a "don't break userland" theory which causes some of the above, but it breaks MY userland memory when I have to learn new tools.
Of course if you stay with Ubuntu you'll find fifty thousand posts on whatever question you have.
This is where the *BSD trees including the kernel and the distribution also helps - they can keep the “user interface” the same while still updating everything.
Linux seems to have to create a new way of doing something because there’s no guarantee they can get the distributions to update the tooling.
I have no idea what it uses as a kernel interface nowadays. Did they change the userspace tool again? This is another reason why I like FreeBSD. The tools and syntax barely changed between ipf and pf and the latter was an improvement. I even use as a gateway instead of an EdgeRouter which I find a nuisance to set firewall rules onto.
Yeah, I'm talking about ipchains -> iptables -> ntfables, not necessarily the various firewall management toolchains on top of those (shore wall, ufw, etc).
Because Linux is the dominant OS on servers (so my dev environment can match the prod environment,) has way more tutorials,and documentation and also has way better hardware support.
I'll agree on the rest, but more docs != better docs; BSDs tend to ship complete manpages without needing to wade through a hundred blogposts (half of which are out of date or slightly wrong).
I’m not really talking about Man pages. Yeah this is the argument the BSD fans like to use but those dozens of blog posts for every Linux question makes it a much nicer experience for new users to get what they want working quickly.
It's not just man pages. I can't speak for OpenBSD and NetBSD since I'm unfamiliar with those systems, but for FreeBSD there is the excellent FreeBSD Handbook (https://docs.freebsd.org/en/books/handbook/), which is great for learning how to set up and administer a FreeBSD system.
If your a new users you should start understanding your system, and don't follow potentially wrong or old tutorials, that's a big problem with the Linux-Information-overflow.
Thae's a nice ideal, but if you need to get something working, nothing beats searching for the error message.
The original package maintainers could write instructional materials that start from the errors, but I suspect that's too hard. Without specific training, it'll always be easier for third parties to provide ad hoc than first parties to produce as part of release.
Some potential reasons for using FreeBSD:
It's the same three firewalls forever, not a progression of different firewalls.
Old knowledge still works, for example, netstat is still the way to list socket connections and ifconfig is still the way to configure interfaces. I did some work with FreeBSD in 1999, and then nothing until 2004, and all the knowledge transferred, then in 2011 I changed jobs and skipped ahead several versions, and again all the knowledge transferred. But I kind of stopped using Linux heavily in 2013, and when I had to work on it at work in 2016, all the tools had changed, so I had to relearn (or just avoid the Linux part of my job, which I had the luxury of doing).
Official kernel support for ZFS.
Receive side scaling support is nice, if you need it; although I guess not a lot of people do.
Different positions on philisophical arguments like an integrated source repository with the kernel and the base userland software, or init systems.