Mostly arrogance that stemmed from the belief (unfounded or otherwise) that they knew more than others and therefore can refuse to do certain (usually unpleasant) tasks or order people around.

For example we had an analyst join the business intelligence team recently, and unlike everyone else on the team she has a masters in finance as well as many many years of experience. She refuses to run financial forecast reports for the executive team because she thinks such tasks are below her, and that others should run them instead. Really nice girl otherwise, but just terrible to work with.

The conversation would go a bit like this:

"Run the reports."

"No."

"This is your verbal warning. The next step is a written warning. Run the reports."

"No."

"I am going to my office to write a written warning, of which you can accumulate two."

Et cetera...

Or:

"Run the reports."

"Instead, can I please help replace this broken system with a modern one that is automated and good?"

"This is your verbal warning. The next step is a written warning. Run the reports."

"Your system for reporting is manual, tedious, and error prone. How could you be proud of this?"

"I am going to my office to write a written warning, of which you can accumulate two."

"The quality of the system is terrible and I can't stand behind it. The fact that you've refused my offer to improve it means that I should probably just leave. I quit."

"Let me fix it." isn't something I'd count as a refusal.

Are you hiring? (At least halfway kidding, but you sound like the kind of person I want to work for...)

I sold and retired, about a decade ago. I am the partial owner of a few franchises. I don't suppose you want to be a sandwich artist?

I have nothing to do with their regular operation, I'm just an investor to help a friend out. I suppose I could get you a job as a sandwich artist, though. Maybe someday you'll make Assistant Manager! ;-)

Err... Your other option is being a logger. However, I don't employ them, they actually pay me.

Exactly. Ultimately, people who work for a company need to follow orders. Managers should strive to avoid issuing orders like this, but if people are exhibiting an attitude problem and not doing the right thing, then they are entirely appropriate. If a person can't follow a clear order, then they're a problem that needs to be dealt with (coaching, performance management, etc.)

It shouldn't be a big deal. The person's manager needs to sit them down and say: "This is what's expected of you. We expect you to run these reports, same as everyone else at your level. I know you have prior experience, but at our company you are <job role / job level>". If they won't do it, fine: "so long".

Yeah, I'm absolutely not going to put up with an employee who refuses to follow orders. This assumes they are lawful and ethical orders, of course. If they are outright refusing, we are going to have an immediate correction or termination.

On the other hand, sometimes you're hiring a professional rather than a laborer.

The difference is they'll do the quitting rather than you doing the firing.

The vast majority of my employees where STEM employees. Programmers, IT, traffic engineers, etc...

There's a difference between 'it should be done like this' and outright refusal. I'll listen eagerly to the former. After all, I probably hired them to do things I could not. If I could have done them, I'd have not needed to hire them. I have no time for the latter.

Your conversation flow relies heavily on the other party doing a solid, succinct, clear 'no'. If only human interaction were that simple...

Brevity was a consideration, but the idea was refusal. If it is refusal, we have a problem. If, as an above poster suggested, there's an offer to fix the system then I'd not consider that a refusal and I'd be a fool to not at least hear them out.