Because it curbs free speech .
No it doesn't. In fact, it is the RW's Talk Show format that is curbing Free Speech according to the Supreme Court.
A license permits broadcasting, but the licensee has no constitutional right to be the one who holds the license or to monopolize a...frequency to the exclusion of his fellow citizens. There is nothing in the First Amendment which prevents the Government from requiring a licensee to share his frequency with others....
It is the right of the viewers and listeners, not the right of the broadcasters, which is paramount.
— U.S. Supreme Court, upholding the constitutionality of the Fairness Doctrine in Red Lion Broadcasting Co. v. FCC, 1969.
Terrible ruling by the court but with the massive amount of liberal interpretations of the constitution during that era of the court it is not surprising.
But it will fall and soon under the 2 (b) and (e) provision of this ruling.
The internet which has drastically improved technology is counter to the fairness doctrine's core argument of "this is a scarce resource". That core argument now is untrue.
First Amendment arguments are 100% correct in this argument as I agree that it is NOT the broadcasters that trump that right here as it is the viewers and listeners.
But media and one's ability to receive "fairness" is not hindered in any way today as one can easily go on the internet and reach tens of millions with their "each side must receive fair coverage" dinosaur of an argument.
Fairness Doctrine will fall flat on the next case. That is why we have not seen any lately.