It depends what your "business grade" is. Server Operating systems are tools to do tasks and run business software. Most "internet" software is written for Linux first *nix, *bsd later. Its become that way because it has the largest deployment base, the largest user base, the most varied user base of all the *nix and *nix like systems (bsd, osx). It tends to be much easier as a developer to focus on the largest user base, then when users come looking for support on other operating systems there is enough momentum to support it.
It has not always been that way, If we go back to the 1990's Solaris was the premier UNIX (Solaris was actually originally BSD based and changed to SysV (UNIX) around the early 90s) and FreeBSD was king of the open source crowd. FreeBSD fragmented [1] massively towards the end of the 4.x -> 5.0 streams, some key developers left the community to work exclusively for Apple [1]. It's multi-core and filesystem reliability was absolutely shocking in early 5.x releases and was only marked -STABLE in 5.3. The poor multi-threaded performance and the new dual core CPU's put a large dent into the FreeBSD community as many users jumped platforms to Linux. With many large organisations backing the project (Linux) it has grown in stability and performance.
As with any OS you need to pick your hardware to match your software, there are always fly by night organisations selling cheap fab crap out of China which is unreliable and has poor or no driver support. This is a key point on Linux desktop adoption. So many "consumer grade" computing systems have shocking driver support and that shows up on Linux, FreeBSD et al.
Disclaimer: I've been using Linux as my primary desktop operating system since 2003. I have been at various times a contributor to projects including MySQL, Slackware, Ubuntu, FreeBSD and Squid. I have developed software since the early 1990s on Linux, Free and NetBSD, SunOS, Solaris, OSX. In that time all my Linux desktop systems have been full intel hardware to avoid driver pain-in-the-arse. Having said thta my work supplied system is a recent macbook pro. While OSX has some nice features it's a poor substitute to Linux as a dev environment. The simple reason is there are all sorts of edge case bugs that arise in OSX that I don't see on Linux (different threading implementations, schedulers, c libs, compilers, the list goes on and on and on). Again the entire tool chain for open source software is generally developed with Linux first all the rest second.. and it shows.
I should also point out that I don't play music or do any photo/video editing on Linux. It's my toolbox that I work in KDE, Browser (Chromium, Firefox) Editor, Shell, Compilers etc. I've occasionally looked over the fence at GNOME/Unity and cringe.
The key point is that there is the right tool for particular people's jobs. There is no such thing as one size fits all in life, and computing. This thread has also gone WAYYYYY off Topic.

