Why oppose ? Well there is the principled stand of not obtaining basic commodities via gross inequity and oppression. Slave societies have in years past been rather comfortable places to live - even those based on offshoring their slaves - but many rejected the needless excess for a few, when derived from human deprivation and suffering for the masses. Eating fruit that is made slightly cheaper by being produced under terroristic regimes which abuse their workers, ignore environmental norms, and kill dissenters is less satisfying, sometimes guilt inducing. The same goes for other commodities: consumers have a conscience.
Then there is the fact is that what usually results from such oppression is unspeakable violence and turmoil.
Just as the Middle East was set onto a period of great instability and human tragedy, much triggered by ill founded U.S. intervention abroad; such will be the case with the U.S. Pink War in Latin America. Like the middle east conflict, certain Latin American commodities may be somewhat cheaper for a time, but there is one significant difference: the waves of instability and tragedy triggered by the Pink War will not be thousands of miles away in the Middle East, rather, they will be right at the shores and borders of the U.S. itself.
There are externalities, or unaccounted economic and social costs of benefiting a few corporations with military or paramilitary backing. The enormous costs to the entire United States has become more well known in the Middle East conflict. The Iraq war's costs alone were recently estimated at 2.4 trillion by 2017, as estimated by the U.S. Congressional Budget Office. This may not include the premiums in gas costs paid by U.S. consumers for several years afterwards, and it most certainly does not include the heartache and pain felt by some of the victims of that war. Or the costs to other countries. Some would debate whether that cost was worthwhile. But at least they could think about it. In fact, the financial costs of U.S. coups in Latin America are usually hidden behind a veneer of 'secrecy.'
The act of employing undemocratic and immoral people has the unfortunate effect of ultimately populating your country with them. The U.S. ends up harboring some really nefarious characters, and sometimes finds itself shielding and rewarding them. The corrupting influence of harboring law breakers at home presents another danger. These individuals can deliver otherwise unattainable results. Today they might be circumspect, but tomorrow they won't have a need to explain themselves: their undemocratic roots will have spread, and they will act to take what they want for themselves. Ultimately the factions controlling them may find that these individuals will splinter off, where repressive personnel, technologies, and know-how are let loose on an unsuspecting democracy: A tremendous threat to all governments everywhere.
