>As an American citizen, I'm still subject to federal income tax, even on income earned while I'm residing outside the country, for work done entirely outside the country, for a non-American employer. That being the case, I see no reason why similar rules shouldn't apply to American corporations. If we say an individual still derives services and value from their citizenship even when outside the country, and thus needs to pay in to support that, why not also American businesses?

Wrong question and answer. Assuming what you say is correct (I'm not a tax expert), the question is why is that the law and how can we fix it? The situation you describe is morally wrong. You are getting no protection, use of infrastructure, or other aspects of the services that our taxes provide. Therefore, you should not have to pay tax. Rather than propagate an unfair situation to other entities, the situation should be fixed. A paraphrase of your comment is: I'm getting treated unfairly, so others should also be treated unfairly.