^ This. Office Excel Guy is just glorified IT help desk. People don't want an explanation, don't want to learn how to use excel necessarily. They want want to push one button, and get a result. Spend longer than 5 minutes explaining it and you will be told you're wasting their time.

You spend time explaining on what is essentially deaf ears, and being on call all the time

Educators tend to have alignment on students' skill levels too, and perhaps not so with "Excel support." It's actually easier to help someone who knows nothing about the subject. What I struggled in the past are those who think they know what they are doing, yet require help in narrower scope.

They often have often accumulated bad habit, and won't listen to you because "I have been doing this way for years."

Also, it's interesting to observe that many who struggle in Excel (or many of "consumer" applications) actually are struggling in basic computing skills. (e.g. can't tell difference between left and right mouse buttons, don't know how to copy files, etc.) It often result in infuriated people, pointing out that they need to learn basics of the operating system.