There was a thread about that on c/selfhosted a few weeks ago. Created by a particular wild-cat-inspired sysadmin, I might add.

But on a more serious note, the interactions between a sysadmin and their servers (that they have enough responsibility for to be able to name) are much more intimate than the interactions between a dev and their variables. The server names also exist in a much larger namespace, so they need to be more unique.