Why is it stupid? They claim to be concerned with trade imbalances, and that those imbalances are a problem. Using those trade imbalances to calculate a tariff seems reasonable, assuming the concerns are right.
If tariffs are to be imposed, I'd at least rather be able to see how they were calculated and know it was done the same for every country.
The "numbers" appear to:
* Punish Ecuador, who uses the US dollar, for being a "currency manipulator", which obviously makes zero sense
* Punish Lesotho, whose population is too poor to ever afford US goods, because they export a lot of resources that we use
* Punish countries like Columbia for being big coffee exporters where there is no hope of building up a domestic coffee industry because that's not how agriculture works
* Tariff an island inhabited only by Penguins
It's just dumb.
It's stupid because trade imbalances aren't necessarily a problem, and are sometimes a good thing that you need.