> Difference between "agression" and "microagression" is one of scale
No, you're comparing physical aggression with verbal aggression. Sure, the latter might hurt, but I think many (most?) people would agree that it's not just a difference "of scale".
> But the intent to hurt is common.
No, "microaggressions" are often accused even when there's no intent to hurt. E.g. asking a foreign-looking student "Where are you from?" - which is most often likely asked with genuine curiosity, and no ill intent whatsoever - even if you don't assume the person is a foreigner!
We teach our children that it's fine to be curious, but not to be rude. People we meet do not owe us any form of entertainment. If we get to know them and in the course of discussion they are inspired to share some details of their origins then we'll learn those details. If not we can just read a book.
I admit that society has been impoverished when rudeness is reframed as "microaggression", but that doesn't excuse the rudeness.
That has always been rude, but is especially so in today's political context. Immigrants of color know that lots of people in Western nations don't want them around. Random interrogations from random white people don't help them feel better about it.
Rudeness isn't the end of the world, but we should still try to avoid it. I don't get pissed off when adults ask me about or make stupid jokes in light of my obvious physical handicap, but I would still prefer that they not do that. Young children get a free pass, because I don't expect them to know any better.
The whole concept of "icebreaker" seems dubious. If you don't feel comfortable around strangers, that's your thing. It's silly to assume that anyone treasures your company enough that they want to become familiar.
No, you're comparing physical aggression with verbal aggression. Sure, the latter might hurt, but I think many (most?) people would agree that it's not just a difference "of scale".
> But the intent to hurt is common.
No, "microaggressions" are often accused even when there's no intent to hurt. E.g. asking a foreign-looking student "Where are you from?" - which is most often likely asked with genuine curiosity, and no ill intent whatsoever - even if you don't assume the person is a foreigner!