It's coming from the people who buy the exported goods.

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".

It's clearly not protectionism, because you wouldn't put tariffs on everything - including all the raw materials and parts you need to import, if you wanted your local industries to succeed. And you'd have a coherent industrial policy to go along with it.