Taken to it's extremity, it's given us corporate personhood via Citizens United, and the codification of the principle that you (private or corporate personage) are entitled to speak freely at whatever volume you can afford to, including explicitly politicized speech.
But more abstractly and insidiously, the value has mutated to give license to liars and manipulators of all kinds. I know there's no way to enforce factual speech in daily life, but the Western ethos of unvarnished free speech has come to mean we tolerate people and companies that just outright lie and manipulate all day every to make a living or a shareholder profit. Sure, the left leaning media makes fun of Fox News or gets worked up about Breitbart, but we have no recourse to the psychological and structural damage they do to our society through their dishonesty. And most average Joes (of whatever political stripe) shrug and say "Hey it's America, we believe in free speech here."