I am sorry but you really are speaking total ********.
The reason ALL BAR ONE website providers use ANYTHING BUT MACS for hosting is because macs are NOT designed for hosting AT ALL, from what I remember, apple has a few apple servers dotted around for their frontmost facing websites and everything behind them is NOT mac.
Honestly do what you like, but please do NOT spread more misinformation. Macs, like windows clients, are built with options designed for a desktop use except the old OSX Server for XServes which they discontinued (Probably because no-one bought them either; overpriced and again very unoptimised for server use).
If you want to learn more about the differences between desktops and servers, get a linux distro installed and compile your own kernel, selecting all the options such as timer frequency, block schedulers, latency-aiming and whatnot and you'll soon realise very quickly why macs are NOT designed to be servers - they come with one kernel and one kernel only.
Major ********, I'm pretty sure just like every other OS, OS X is definitely usable as a server.
OS X may be not designed for the server, but with the system itself I can do anything. I have a Mac because I also have to develop for the mobile.
Since when was OS X Server discontinued?