Using cross-cultural fluency to defend Richard Stallman, who doesn't care one iota about cross-cultural fluency, and constantly embarrasses people inside and outside his own culture, is weird.
From within Richard's cultural frame, he's doing the right thing in both the large and the small.
Making people feel uncomfortable, embarrassing people, and otherwise are perfectly valid tactics for achieving change in many cultures; just not the one you're from. The extreme emphasis on politeness is very Western (although many Confucian cultures have something similar in the concept of face).
And although it might seem weird to you for me to be making arguments from cross-cultural fluency, Richard would be a hypocrite if he were making an argument from cross-cultural fluency, but he's not, and I'm not Richard.
I've made the same argument to Americans acting inappropriately in all sorts of countries, even though in many of those cultures neither had (not, often, valued) cross-cultural fluency. I'm sorry, but you're being wrong in both the large and small things, just as much as an American in Iran or Japan expecting everyone to behave like them, and talking about how people are either jerks or overly generous when they behave differently, or when Americans talk aabout how cultures have bad attitudes towards children/women/education/civil rights/etc., or are just plain weird.
If it makes you feel better, Richard is verbally hostile towards men too. The "verbal abuse" is equal opportunity.
And all that said, a lot of immigrants get fired in the US for what's perceived to be inappropriate cultural behavior here. African Americans too, for that matter. Many communication styles are perceived as verbally abusive within US culture. That doesn't make it right.