You cannot solve bullying by banning words. Especially in cases when those words are used in an entirely different context, having an entirely different meaning, without any profound malevolence.
White people don't get to say "nigga - no, it's okay, I'm not saying nigger!"
The other confusing thing here is that people are asking for the freedom to do what they like with someone else's property, and when that person asks them to modify their behaviour they lose their shit.
This is just github saying "no shirt, no service". What happened to "their servers, their rules"?
Seriously, advance directives give doctors useful information about keeping you alive / letting you die.
Don't say things like "no heroic measures", because that's a rare occasion. Be specific.
You're right, though. Those doctors were wrong, and that's why it's a thing. They should have involved the patient, and the family, in the decision.