A lot of it has to do with standardization and training. If you go with Red Hat, for example, you get a bunch of certifications and training materials and stand

A lot of it has to do with standardization and training. If you go with Red Hat, for example, you get a bunch of certifications and training materials and standardized tools like Satellite and so on and so forth. It's easier to find solutions and peace of mind when you get some guidance from a vendor. It's similar to managing a network with Windows technologies. Many of the choices are already made for you. If you go with Debian you have to spend more time building your own stack which is fine if you're experienced and you know what you're doing or if you're the lone IT guy. But if you build a stack for a team then you have to make sure that your employees and new hires know not only the specific stack that you built but also how to find support for each of the individual components. If you go with a heterogeneous environment that consists of several distributions like a mix of Red Hat, Debian, Ubuntu, Arch, etc., then you'll be tempted to jump out of a window.