It's worth mentioning that OpenBSD doesn't support a lot of the hardware people use, doesn't support a lot of the applications people use, and is a fairly specialist distro. They do some awesome things, but they also benefit greatly from not having to support regular non-techie end-users.
Edit: As an example, the upgrade process that you have to do at least once a year[1] is hardly something that a tech naif would find painless
And what hardware it does not support? And what applications it does not support? I'm tired of this meme. OpenBSD runs on virtually everything you throw it at, and virtually all open source is supported.
In some cases OpenBSD hardware support is better. E.g. I have a few laptops where suspend only works in OpenBSD, but not Linux. Also a few years back my WiFi cards were supported natively only in OpenBSD, not Linux. For other hardware, it might be the other way around, but overall it's pretty unlikely to find something OpenBSD does not run on.
And for software, it's exactly the same. Sure there's some Linux-specific software out there, but the bulk of it, is not.
Hipchat and Skype were two popular applications that I used today that don't run on OpenBSD. I ran them on my laptop with an nvidia GPU, which isn't wonderfully supported by linux, but it's even less supported by OpenBSD. Nvidia is a pretty damn common brand. Flash, for all it's sins, is still popular and not supported properly. Steam is another popular application that doesn't work on OpenBSD. Admittedly you said open source, but frankly, I didn't. I said 'applications people use'. It's utter bullshit to move the goalposts and then chide me for inaccuracy.
Then there's virtualisation software in general, which is increasingly popular and widespread, which OpenBSD doesn't support well, if at all (kvm, xen, vmware, virtualbox, and friends. qemu by itself is s.l.o.w.). Docker and other containers are really taking off at the moment and have a lot of mindspace, though admittedly these are linux-specific. Openstack is another significant emerging bit of software that doesn't support BSD as a host.
Then there's plenty of stuff like this http://blog.lxde.org/?p=1111 where OpenBSD could be better supported but is a broken experience. Legitimate reason, sure (not enough eyes), but it's still a broken experience.
It's worth mentioning that OpenBSD doesn't support a lot of the hardware people use, doesn't support a lot of the applications people use, and is a fairly specialist distro. They do some awesome things, but they also benefit greatly from not having to support regular non-techie end-users.
Edit: As an example, the upgrade process that you have to do at least once a year[1] is hardly something that a tech naif would find painless
[1]http://www.openbsd.org/faq/upgrade56.html