I feel that conflating tariffs with some sort of negotiation tool to bring about positive global change is disingenuous, because the real aim is clearly protectionism.
This would mean, of course, that the people who happen to work for an export-oriented factory become much more wealthy than most people in Lesotho. So you might reasonably wonder whether it's better to make twice as many workers half as wealthy. Labor advocates believe the answer is no: paying some people genuinely good wages both creates and encourages further development, while paying a larger number of people "good enough" wages encourages poor countries to race to the bottom competing for the lowest standard of "good enough".
Putting tariffs on places that have a 20x factor difference in wages is something else.
And protectionism isn't necessarily a dirty word. It's often valuable to save your local industries from being wiped out and to not have a foreign country have complete control of a necessity.