People are free do to LOTS of things here that would get them imprisoned, tortured, and / or killed in many other places.
But I've noticed that many who are free to "hate" America and burn the flag are in no hurry to leave here. They are ironically most likely govt parasites, govt employees such as teachers or professors, or among the latest generation of some immigrants (certainly not all) who come here for money and opportunity and find it, yet strangely hate the country that gives them such opportunity.
Just like people who hate capitalism who drive Daddy's BMW down to the mall and use his credit card to buy an overpriced coffee at Starbuck's, plus overpriced clothing at Dillard's and an overpriced smartphone made by the slave labor of communist countries they claim to love so much but are in no hurry to leave the US for.
Or people who hate both capitalism AND fossil fuels who own several mansions, a private jet, and a fleet of sports cars (usually bought with inherited money) who take their limo down to the climate change protest and tell everyone else they need to cut back on CO2 emissions, as they flatly state that they will give up nothing themselves.
These are usually among the same people complaining about income inequality and everyone needing to pay more taxes. Yet they refuse to pay their workers any more than they have to, and refuse to pay any more taxes than they must, usually taking every tax break they can - even though they are free to pay more tax and pay their workers as much as they wish.