The human then has to write down a long string of unrelated numbers and letters and track it down somewhere in the server room. Both are time-consuming and error prone.

It's annoying enough to try to find "snowwhite" amongst 40 servers in each of 40 racks; trying to scan the list of names for "ABC123XYZ987" when none of the name correlates with any useful information would be absolutely maddening. Jesus christ, I can just imagine for every sever looking at the name on a sticky note, looking at a tag name, and then looking again at the sticky note and back to the tag name, possibly a third time, just to make sure it wasn't off by one number or letter or something. Repeat for thousands of servers? Euuggh!

Besides the poor cage monkey having to deal with that crap, when you're fighting fires in the ops room you need to be able to refer to a handful of server names quickly. You can't be copying-and-pasting names to people, looking information up every 2 seconds because you can't possibly memorize it. We are human beings and so we need human interfaces to information.