what makes you think they aren't? I work for Red Hat. It is an amazing company to work for. But our main technology center is in the Czech Republic, where the cost of living is 40% lower than the US. Those are absolutely great engineers to work with, and despite some of the alarming comments here they are absolutely as high quality as any US engineer if not more so. But the fact remains that their salaries are spent overseas and not here in the US.
This is why the point of free trade is to raise the standard of living in those nations so that not only does life get better for everyone around the world, but also other nations no longer act as a cheap drain for jobs that pay artificially higher wages domestically. It's a huge idea that has worked in many ways, raising US GDP vastly beyond what it could be under heavy protectionism (think: the whole world as your customer base as well as your production base vs. just the US). But it also failed spectacularly in that it isolated low skilled workers in the US who became even more resentful of foreigners than they already were, who then went ahead and elected a facist government. Whoops.