And, in a country as large, diverse, and successful as America, only a small percentage have sufficient honesty, maturity, and humility to make them remotely capable of contrition.
And then there comes the question, to whom should they repent? Many haven't been introduced to God...yet
As a country, we can afford to bear a certain number of dumbasses and evil people and be fine. We’ve always had them, even when the country was founded.
However, when enough people have adopted unwise values, the accumulated weight of our dumbassery ensures our destruction eventually.
God told Israel to repent as a nation, so we, as a nation, have that same responsibility whether or not we can convince enough people to repent as individuals to avoid destruction.