I admire Chomsky, but I admit he didn't answer this dishonest question (excerpted from this video) very well. That's partly because it's constructed like "Have you stopped beating your wife?", beginning with a false premise. Chomsky doesn't say that America is a terrible country: he freely admits that the US is a free country, perhaps the freest in the world. It is rich, and of course many people have wanted to come here. What he says is that America has done terrible things.
Perhaps one way to answer the question would be to ask why, since America is such a great country, it has done and continues to do such terrible things. One might also ask what should be done to a country that does such terrible things. Most Americans and American apologists have no doubt what should be done to other countries that commit crimes: sanctions, invasions, bombing, missile strikes, "regime change." They have trouble coming up with plausible reasons why such measures should not be inflicted on the US.
But then, they don't need plausible reasons. Like any good team players, they think that a loss by their team is a disaster. Sometimes I'm surprised that sports fans are able to tolerate another team's daring to try to take the victory from their guys at all. They cultivate an inability to imagine sport, let alone the world, from another person's point of view. Apologists for sport are mostly as dishonest about this as apologists for their country's violence.
Maybe an analogy or two will help. Germany is the most civilized nation in the world. People everywhere look up to it for its intellectual, cultural, and political accomplishments. How can you call it barbaric, brutal, murderous for a few little missteps that any nation might have made?
Or: For almost two hundred years, millions of people have been inspired by communism to fight for the oppressed and downtrodden. Sure, it isn't perfect, but if it's so terrible, why do so many people still -- even after the fall of the Soviet Union -- look to communism as humanity's best hope for a better world?
There are plenty of reasons why poor people, people in danger of their lives from religious or ethnic terrorism, people wanting to avoid conscription into the army, would have wanted to move to the United States despite its flaws. One might be that they were more concerned with saving their own lives than with the harm the US did to others, and indeed might have figured that they were not likely to be the targets of US violence once they had immigrated. European whites were not likely to be enslaved, or driven onto reservations. Maybe they didn't care what happened to other people as long as they and their families were relatively safe.
Or maybe they had unrealistic ideas about the US. Moving here often meant a fall in earnings and status, as many Europeans and (later) East Asians found to their consternation. They were doctors or lawyers or other professionals in their home countries, but ended up working in sweatshops, running convenience stores, or driving taxis because their credentials weren't valid in the US, and their English wasn't good enough to acquire new credentials here. But they couldn't go back, either because there was nowhere to go back to, or because they didn't want to lose face. They may have borrowed money from relatives to make the move, and had to pay it back. (Some did go back anyway, but they seem to have been the minority.) But none of this has any bearing on the bad things that America has done.
It's understandable that people would not want to believe anything bad about a country or a person in whom they've invested all their love and admiration. If that person, or that country, is proven to have done terrible things, they don't give up their adoration and allegiance lightly. They blame the messenger, often harshly and hatefully. It's understandable, but it's wrong, and should not be tolerated. In the case of Stephen Sackur, the BBC interviewer here, it's not entirely clear whether he had even that excuse. He's English, so he should be capable of some critical distance from America. Maybe he thought he was playing the devil's advocate, giving Chomsky a chance to answer a charge that is commonly made against him.
In all this, it's ironic that many of the people who hate and lie about Chomsky, and about all critics of US foreign policy, nevertheless hate the US government and lie about it. Recently a right-wing Christian with whom I went to high school posted on Facebook one of those absurd stories that many people love: a convoluted tale of a smart-aleck farmer who meets what turns out to be a rich city slicker from the US Congress, and tells him off (eviscerates him, destroys him, bam boom burn!). It's a familiar theme, going back to the Eloquent Peasant stories of ancient Egypt, and persisting in the Marine Todd and That Student Was Albert Einstein urban myths of today. It's very popular among people who are basically ignorant about ideas and the world. Yet this guy and those who share such stories generally love a rich city slicker like Donald Trump, and even right-wing political and cultural figures who have enriched themselves at the public trough, and they are indignant if some radical liberal criticizes them.
That indignation is reciprocated by liberals who don't like it if some Rethug mocks rich city-slickers like Barack Obama and Hillary Clinton, whom they work very hard to see as Just Folks. An attack on their idols is an attack on Regular Americans like themselves. Despite the popularity of the term in lefty circles, I don't think "tribalism" is the right word for this pattern of thought. Until I come up with a better one, though, it's important to keep challenging and trying to refute those who justify American (or any other country's) atrocities by minimizing them.