Governmental control over the 'decency' of content in broadcasting is a form of censorship, which is an intrinsically immoral practice. To force broadcasters to censor their language or content is to compel a unified opinion in the society on the matter of moral decency, one could argue that this is a violation of the First Amendment. Our Media is a social institution, and what practices are made acceptable there become acceptable in all of our social institutions, including the family, or education.
Language is a limited enough medium for communication already, before compounding that limitation with regulation. Our language is our most precious treasure. No society which considers itself modern or enlightened may operate morally while employing censorship.