That's not what Justice Sotomayor said in so many words, but it's pretty darned close. Once an advocate of video coverage, her time on the High Court has her seeing it differently:

She was singing a different tune a couple of weeks ago, telling Charlie Rose that most Americans would not understand what goes on at Supreme Court arguments and so there was little point in letting them try.

“I don’t think most viewers take the time to actually delve into either the briefs or the legal arguments to appreciate what the court is doing,” she said. “They speculate about, oh, the judge favors this point rather than that point. Very few of them understand what the process is, which is to play devil’s advocate.”

Yes, viewers may misconstrue intent of a line of questioning. And they may not have all the back story. I've also seen a gallery full of citizens completely misundersetand actions a city council was taking; does that mean those should be closed? Perhaps video access to SCOTUS might actually help educate citizens as to what's going on!

And what does Justice Sotomayor care if the public gets it wrong? She and the other eight justices can't be voted out of office. Classic liberalism; the public can't be trusted with the the facts.