No American corporation should be allowed to incorporate somewhere else in order to avoid taxes. Let them sell their goods and services where they are incorporated.
That may work if money-hungry governments didn't keep jacking up taxes and simply assuming the corporations will pay them. The choice isn't operate in a high-tax jurisdiction vs. a low-tax non-US jurisdiction. The choice typically is operate in a jurisdiction with reasonable taxes or go out of business.
By the same token, the U.S. should not tax a U.S. company located in Germany for making a product in Germany, and selling it there.
Congress doesn't give tax loopholes to generic drug manufacturers because generic drug manufacturing is cutthroat competitive and they don't do a lot of campaign contributing.
OTOH drug manufacturers with very profitable patented drugs(like Merck and Pfizer) do get loopholes plus extended patents so they do make campaign contributions.
Meanwhile, in Europe, the tax code is more uniform(fewer loopholes) so a generic drug manufacturer has relatively lower taxes there.
So, we are talking about institutional corruption or systemic corruption or legal corruption and no one is better at it than the US Congress.