The limited liability corporation is a wonderful invention, which has made us collectively much richer than we would have been otherwise.
The limited liability corporation is a legal person. As a legal person, it cannot have all the rights of a natural person, that is, a human being. It cannot enter into marriage, for instance.
The limited liability corporation is the creation of legislation. As the creation of legislation, it cannot be other than a person for commercial purposes only. It is a person so that it can enter into contracts, for instance, and so that lawsuits can be brought against it.
Under our system of law, the role of judges is not to legislate but to interpret legislation.
I submit that judges who decide that corporations are persons for purposes other than commercial ones are engaged in “a naked usurpation of the legislative function under the thin disguise of interpretation,” to quote Lord Simonds’ magnificent put-down of Lord Denning in Magor and St. Mellons  A.C. 189.
I submit that any judge who would interpret the personhood of a corporation so as to attribute to it the right of free speech other than for commercial purposes, say, is as daft – and acts as unlawfully – as a judge who would give corporations the right to marry.
I submit that it is the duty of superior courts to quash extravagant interpretations of corporate personhood by lower courts and that, if it is the highest court that has been extravagant, then it is its duty to reverse itself. It is the duty of the legislature to explicitly reject the extravagant interpretations.
“Realists” will retort that these things will never happen but sometimes the first step in achieving a goal is stating what ought to be the case.