I disagree. Perhaps that is because I see how these systems get used in actual production environments. While it is true that we don't touch upon subjects like 'racks of servers' as the typical use-case is doesn't mean that it isn't done on ClearOS, SME, NethServer and other similar boxes. For example, I can set up 10 ClearOS servers at multiple locations with integrated directory services, PDC/BDC operations throughout and site-to-site VPN tunnels at to different locations all with relative ease. While this isn't racks of servers, it does require, and these solutions do provide, standardized deployment scenarios for Server Management. For me, server management has less to do with 'intimate knowledge' of a thing and more to do with 'ease of use' in deployment, reporting, and day-to-day tasks. That is what ClearOS, SME, and NethServer do, we are all about making it very, very easy to use and very easy to manage. The fact that our sweet spot happens to be in enabling Linux Server Management to those that are wholly novices at Linux (in general) is reason why this type of server management is needed; to grow and expand the use of CentOS and Linux in general. The lesson of Darwin (MacOSX) and Android is that the more manageable the experience is for the user, the more it gets used.
You do raise an important point about the aspects of our systems that is lacking and that is in the multi-server management space. Instead of calling that 'Server Management' (which to me means the management or manageability of a server) I call it 'Rapid Deployment and Automation'. Managing multiple servers through an intimate knowledge of Linux voodoo falls in this category. Here we can turn to Puppet, Saltstack, Kickstart and others. Many of these solutions and vendors don't consider themselves "Server Management" but rather 'Automation.' We'd love to be able to ALSO integrate these functions within our environment. Hopefully, working together in this SIG space, we can come up with some standards and best practices to benefit us all in greater adoption of these tools.