This was during the windows XP era when it seemed there were an endless number of security problems related to usb devices, no matter how good the group policy and registry settings pushed via active directory membership were.
Here's a current story:
Someone ordered the wrong desk phones at your large company?
1.) Assemble your crew. Go to various departments and recruit non-technical people.
2.) Task them with disassembling 1000 desk phones.
3.) Hot glue USB port on phone shut.
4.) Reassemble 1000 desk phones.
The safeguard doesn't need to be perfect, it just has to be good enough.
While these second order effects are immeasurable, they are quite tangible in my personal experience.
Attempting to authenticate USB devices is a very hard problem — a sufficiently advanced attacker can spoof manufacturer and device IDs, even if you lock things down to prevent anything other than a keyboard or mouse it's possible to send keystrokes to open the wrong website, there's always a chance of an exploitable flaw in your USB stack, etc. — but anyone diligent can be paid to walk around every week checking to make sure that a seal is solid and the tamper-evident stickers have the same serial number as listed on the inventory. There is a real value in having things where the failure modes are obvious and intuitive.