Capital is mobile. If the US decides to tax dividends unfairly (versus other economies), if it decides to tax offfshore earnings, if it decides to increase taxes on salaries (such that the cost of business increases - ie workers will want the same take home pay), then businesses will start moving their headquarters out, as well as all the administration type jobs that go with them.
You're exactly right but this isn't what will happen, it's what is already happening. It's too bad our lawmakers can't figure this out.