Imagine something happens to you, something not that serious but still serious enough to make you go into a panic, like you suspect there is a spider under your chair. The person next to you says “calm down”. Would you be angry at that person for telling you to calm down while you are clearly not calm?

I had an argument with someone about this. That person thought it is rude to be told to calm down while they are panicking, and that does nothing other than piss them off. My argument was that at least someone is trying their best to calm you down, so you should at least appreciate that they tried, and you are just being an ungrateful snowflake for shooting someone down for helping you.