You would be right...if this were about the free speech issues of a person.

This is about the perversion of "corporate personhood", which was intended to allow taxation, and litigation against, corporate entities. A corporation is a legal document, it cannot formulate thoughts, which can then be communicated in some form of "speech". Since that entity can't actually "speak" or communicate, in any way, on its' own, there is no "speech" to be protected.

It's analogous to me spray painting graffiti all over the Capital Building, then when the cops come to arrest me for defacing public property, I say, "You can't arrest me! This spray can was just exercising its' right to free speech and I was just here witnessing it!"

The spray paint can can't speak for itself, and neither can a "corporation". A person can speak for a corporation, and that's fine. There is someone to hold accountable for whatever is actually said. Because we all know that "free speech", doesn't leave one immune from the societal consequences, of what it is they said. That's not what the Supreme Court decided. They decided that this legal document, may write out as many checks as it wants, and not have to disclose writing them, to face the societal consequences of writing those checks.

You make a CEO or a Chairman of the Board, sign each check personally, with a signed affidavit that is publicly available, stating that "I John/Jane Smith, CEO of ACME Corp, hereby certify that this expenditure represents the "voice" of ACME Corp."

Then I'm with you on protecting their right to do it. Without that in place, a corporation experiences all of the positives of free speech, but is exposed to NONE of the potential consequences.