People in general will choose what they think is their best available option. Corporations are run by people.

After nearly 20 years studying government and laws, and over 10 years as a lobbyist, one of my cardinal commandments of good lawmaking is "Do not make rules you cannot enforce."

If corporations can en masse avoid taxation then it is either a tax law problem or an enforcement problem. The corporations? They are behaving exactly as they should be expected to act. Of course this kinda highlights that they are soulless and unpatriotic, but it is what it is.