Is it really that fragmented? There's essentially RedHat, Debian, and Slackware. At the level of app development for servers, everything seems pretty compatible.

As a desktop user I just switched from Xubuntu to Debian+Xfce and it's nearly identical.

I'm sure that people who work at the OS level see a lot of fragmentation and headaches, but to their credit it's largely hidden from the masses.

I think the opening for FreeBSD and everyone else is that with containers and virtualization, the movement is towards picking an OS per app, not an OS to run your entire business on.