Most people, (rightly so), react poorly to an ultimatum. That is because an ultimatum is an emotional offense, a deliberate break in a relationship. Do this or else! Do this otherwise! Its either my way or the highway!
There is a difference between an ultimatum and a choice, an ultimatum is not a true choice. An ultimatum does not leave much room for choice, and the options (in an ultimatum) are not usually pleasant.
Often, our instinct is to respond to confrontation with confrontation. Ultimatums seldom work because we react to the emotion instead of responding intelligently.
The difference between responding and reacting to situation is usually the difference between a choice and an ultimatum.
On the other hand, giving your partner in a negotiation or a sale a choice between two outcomes is a generous act, a form of truth-telling that helps both of you.
We all make choices, and choices have consequences. This is not a consequence-free life. Helping people understand the consequences of their choices in advance leads to better decisions.
Instead of “my way or the highway,” maybe it will be better to also add “your way” or “our way” on the list of options.