Does it bother your if your job is taken by somebody else in your town if they can do it more efficiently than you can? I imagine so—nobody likes losing a job—but would you think that the government needs to step in and stop your employer from trying to be as efficient as possible, at making a profit, and at providing goods and services to consumers at the lowest price possible?
Would it bother you if your job was taken by somebody in another country? Why? What’s the difference whether they are your neighbor or somebody in another hemisphere? That the work gets done, is what’s important. The increasing exportation of labor-intensive manufacturing is a sign of increasing prosperity, not decreasing prosperity.
The reality is that purist economic theories exist in vacuums, totally divorced from all the sectors of the real world they supposedly "study". Economists are totally useless, usually worse than useless, when the realities of business, markets, domestic policies, international relations, etc., don't match up with their theories.
Real life is more complex than their laboratories and think tanks.
Most of us who have bothered to get real educations actually have studied economics, but as an addition to other fields of study, not as a total replacement of such, along with total rejection of common sense and observation.