That's true! I only experience the UAC when I install something,
including some, but not all, program plug-ins or add-ons, and some, but
not all, manual updates for other software.
However, in a large office network environment, their are often a few
users that keep playing with the settings, changing the wallpaper, using
the recycle bin as a folder, etc. These people are innocently clicking
yes to *install* a wallpaper image because they won't listen to anyone.
They frequently add third-party toolbars for the fun of it, stick big
magnetic adverts on the sides of their computers, and forward every email
to everyone in their address book, but only after they click the link and
watch some specialty videos that only run after you *install* the update
for the player, conveniently located on the site, of course.
When I was in charge of a small network of only 8 computers, a server and
three printers, I spent more time fixing user meddling than actually
updating or patching anything.
Computers don't need admins, but users sure do!