Note that Hershey's moving only works out for them if the resulting change in labor situation means that their customers can still afford their candy. If the excess labor instead means wages at home go down and now people cannot afford candybars it doesn't work out for them.
In short, we are better off for not having Hershey's in the US. Mexico gets better wages (more competition) and out people are freed from making candybars and can move to more productive uses of our people.
> ...freed from making candybars and can move to more productive uses of our people
relies on the presumption that there is sufficient local demand for laborers (who may not necessarily have any experience that doesn't involve the manufacture or distribution of chocolate) in positions of increased productivity.
The decaying socioeconomic situation for wide swaths of the rural US suggests that this was not the case.
US rural areas face a very different issue: high wages relative to other countries (shared with cities), but with the population density advantages of cities. I don't need to look to tell you Hersey didn't move to a rural area of mexico they moved to a city of some sort. They don't need the largest city, but a small town cannot supply their labor needs.
An issue with this type of analysis is that "them" is ambiguous.
Even if the candy company folds in 5 years, part of "them" is probably still ahead - the management team "them" experiences gains through short-term incentives for performance while the ownership part of "them" suffers losses.
In some cases, those owners aren't fat-cat capitalists - they're workers' pensions and retirements funds.
In these cases, "we" didn't end up being better off by the company moving to Mexico.
Also, the claim that this type of relocation "frees" local labor from the toil of candybar-making to focus on real value creation is a stretch. More likely, they're now free to compete in a smaller labor market and superficially one would expect that to drive wages down (since the demand for jobs hasn't changed and the supply has of them has gone down).
In short, we are better off for not having Hershey's in the US. Mexico gets better wages (more competition) and out people are freed from making candybars and can move to more productive uses of our people.