Typically with this sort of thing (not just in the US but other developed countries) -- you don't have the correct visa for the work that you're doing -- you're given 72/48/24 hours to leave the country and that's that. (If you don't leave, then there could be more serious consequences.) And usually this happens at the company level -- in other words, the company is responsible for its employees' visas, and told they need to get their people out within X time, or otherwise come into compliance immediately.

But the way that this was handled was completely out of hand, treating the employees (who have the paperwork handled by the company anyway) as common criminals, and to a country that's an ally (and one that you're trying to get to invest in your country), is completely ludicrous in a developed country, the type of action you might expect in the DRC or Myanmar.

And the fact that ICE said it took "months of preparation and coordination", means that they knew these people didn't have the proper visas and instead of warning the company to take its people home and/or come into compliance, they planned a high-profile military-style raid.

I'm not Korean but I can easily see how this would make Korean companies and their employees want nothing to do with the US.