The sentence you quoted didn't say an ultimatum is abuse, it said to reject an ultimatum if from "an employer or abusive romantic partner" with "power" over you

The sentence you quoted didn't say an ultimatum is abuse, it said to reject an ultimatum if from "an employer or abusive romantic partner" with "power" over you. As you say, an ultimatum isn't necessarily abusive. We all have things we want in life - and some of them are deal-breakers for a relationship. But if you read the sentence as written, I think it's solid advice - don't agree to something when someone is leveraging "power" over you if you can avoid it. That is abusive. People who've been in abusive relationships can read the difference between a "this is make-or-break for the life I want, you need to make a choice" and "I'm abusing this situation to make you agree to something you don't want to do / is bad for you."