To counter your opinion, I will quote to you from the Universal Declaration of Human Rights:
> Everyone has the right to freedom of opinion and expression; this right includes freedom to hold opinions without interference and to seek, receive and impart information and ideas through any media and regardless of frontiers.
The US Bill of Rights is simply an acknowledgment of the inalienable right to free speech, is it not a definition. The role of the US Constitution is to define the powers of the US federal government. The absence of a protection from private attacks on free speech is not an endorsement thereof. It's simply the nature of the document.
All too often I see the expression, "freedom of speech is not freedom from consequences." In fact, that's precisely what it is. The freedom to say what you want without being punished for doing so, whether that punishment be execution, imprisonment, social exclusion or anything else. Society seems to be accepting some limitations to free speech (i.e. shouting fire in a crowded theater, personal political opinions having professional ramifications, etc.). If we've decided, as a society, that it is necessary to limit free speech then let's be honest about it. We should not present those limitations as some inevitable part of having free speech in the first place.
Freedom of speech is freedom from consequences. That we have decided consequences are sometimes necessary is a testament to how much we value freedom of speech.