The reason we got into this business is we like administrating machines, and don't need fancy GUI tools to do our job for us. We do use usermin, to let our customers manage their own accounts, but cpanel, et al. make it hard to provide the specialized accounts that we provide.

We recently had the opportunity to work on a server that was configured by confixx. The problem that would normally take 10 minutes to fix took 5 hours over the course of two days, due to the GUI that makes it significantly harder to set up wild-card subdomains, and the recommended method is much harder to maintain than the way an admin would regularly setup Apache.