Because these other countries are not as wealthy as us American consumers, we will always buy more of their goods that we want, than they will of our goods, there will be some widget trade deficits for us....
And because the USA has other strong businesses of SERVICE that we make money on, protecting our own widget selling is not as important to us and our economy as it is to their countries....so they need to turn to protectionism (tariffs) on their key products, more than we do....
And there are countries we buy certain things from that could never be profitable or even capable of producing in America....
i.e. Madagascar Vanilla Beans...can tiny little and poor Madagascar ever be able to afford to purchase as much from the US as we buy from them? NEVER! We will always have a trade deficit with them....punishing them with tariffs on a product we can't even grow well in the US, and US consumers WANT, is stupid.
Strategic tariffs are sometimes necessary for these other countries, and yes....some times necessary for us.... But tariffs across the board on countries who can't buy from us...(the big consumer machine that we are), as much as we buy from them is ridiculous and again, stupid....imo.
