All that Citizens United means is that corporate persons can speak freely to the same degree that natural persons can. Which makes sense, collectively speaking is just as core to the First Amendment as speaking alone is.
Agreed, I've found that much of the criticism of Citizens United isn't very well-informed. In a way it's an embarrassment that the Supreme Court had to affirm that a First Amendment right extends to corporations, because it's right there in the plain text: "abridging the freedom of speech, or of the press". "The press" has always, universally, been understood to mean publishing, which is a business, and hence a corporate practice.
It was naked partisan suppression of speech to rule that Fahrenheit 9-11 is protected speech but it's 'electioneering' when Citizen's United funds a documentary. Not that I'm a fan of Citizen's United, quite the contrary, they started the whole brouhaha by suing to prevent Moore's advertisements from showing before elections. But the grounds the FEC used to dismiss that suit were equally applicable to Celsius 41.11, it was a clear-cut case of administrative overreach.
You can't have freedom of the press if the government is allowed to decide which corporations are and are not "the press", that's a loophole you could barnstorm a Saturn V through.
