But you're claiming that for a company there shouldn't be a choice, it should just lead to termination.
Accepting a resignation achieves three separate objectives:
-resolves the ultimatum
-discourages future ultimatums
-preserves the status quo ante
In every employment contract there is a balance of things and employee is willing to do and an employer is willing to provide in exchange. If my boss said that they wouldn't pay me anymore I would rightfully respond with an "ultimatum" of "pay me or I quit". That's the ultimatum they respond to every day by paying me; they look at the balance of things I offer, consider what I provide to the company to be adequate, and then give me the money I ask for. The same is true for any ultimatum: you come to the table with one final negotiation; the negotiation of "do you value me? Then you must provide me this". It's an entirely transactional exchange.
Now, ultimatums are general to be discouraged not because they undermine some sort of authority, but because they are a sign that negotiations have broken down on both sides. As a manager, your goal should be to try to reach a compromise far before that point–not only does to hurt your relationship if you don't, even when the ultimatum is "successful" from the point of the employee, but by letting a conflict reach an ultimatum point you're exposing yourself to significant risk and often poor deals. The way to handle an ultimatum is to forestall "pay me x or I quit" with "I'll pay you almost x if you show good performance for the next three months". If you are at the point where the argument is "I'm going to quit" then yes, you may have to carry through with the termination if you think what they provide is less valuable than what they want from you, but you should really be looking at what you did to get to that point instead.
Yeah, and whether intended or not, a "fire anyone who gives you an ultimatum" strategy absolutely creates that vibe.
If you have a top down management style where you employees do not question anything you say, that might be the way to go, but I find in the software business what you want is the opposite. You want all the criticism and feedback you can get from your skilled and knowledgeable work force. If you don't get that, you're wasting the majority of that money in their pay check.
The irony here is that if you have a manager firing someone who presents an ultimatum, then tat in itself is effectively an ultimatum that you are supporting. ;-)
That of course also doesn't mean you accede to every ultimatum. I mean, if your business plan is to do X, you want employees that will help you to do X. If they are getting in the way of X, then you need different employees anyway. Usually though, you and they have already worked out that they want to work with you to help you do X before you hire them.
So the main reason you get ultimatums is because they didn't anticipate and do not like the approach you are taking to get to X. Assuming they are smart and have good judgement (and again, if not, why did you hire them? why are you paying them?), there's a very good chance that there are some problems with your approach and you'd be wise to at least consider that possibility and their perspective. They may be trying to save you from making a terrible mistake, and feel like it is incumbent on them to stop working for you because allowing you to proceed would be working against that goal you hired them for.
It's not uncommon for two people to have very different perspectives on what helps to achieve a company's objective. It's also not uncommon for one of those people to be horribly, horribly wrong. Sure, if you've got an employee who has presented an ultimatum based on horribly wrong judgement, it may make no sense be their employer.
I'll tell you though... just because their a subordinate doesn't automatically mean they are the ones exercising horrible judgement... and the farther you go up the food chain, the more severe the consequences from supporting someone's horrible misjudgement. So having a policy of summarily firing subordinates who present ultimatums both creates the wrong environment to get the best out of your team and terribly harmful for the leadership of your organization.
Usually the goal of management is to employ explicit, stop-gap communication to avoid having to get to the explicit question of continued employment, because the company has already made a committment to that employment by hiring the employee in the first place. Obviously, most employees want to continue on, also. So it seems nonsensical to view anything save an explicit declaration of resignation as the same. "I would like to discuss what would cause me to resign," is not a declaration of resignation, and the people reading this situation in good faith understand that.
You might think that's exhausting, I certainly do, but that's what we're dealing with here.