Whether it's a tragedy of the commons or not is orthogonal (IMHO) to a question of morality. Same with legality.
I don't disagree with what you're saying otherwise.
I don't disagree with what you're saying otherwise.
Example: A company, acting "morally" as you define, pays more tax than it is required to under the law. In so doing, it incurs a loss so severe that it must cut staff in order to remain viable. Among those employees cut are some of the more vulnerable - those with low savings, poor health, or babies on the way.
Has the company acted morally?
Consider another issue: Should the same company pay more than its legal obligations in every jurisdiction to which it is subject? How should it allocate its extra giving? What if, in some of those jurisdictions, there's a good chance the extra money will simply go into private pockets via graft and corruption, instead of serving the public good? (There are such jurisdictions in the EU, yes?)
These issues are not as clear-cut as you suggest. It's far better for the tax law to best reflect the morality of the citizenry, and then fully excuse the citizenry (including business entities) from seeking to legally minimize those taxes.
Usually not an issue in this case, since corporation tax covers profits. If anything, corporation taxes encourage greater employment.