No, he's right. I have a friend who does voiceover work and is and announcer for the UK Channel 4. He does all his work from home using an ISDN link. It's a huge pita for him because the telcos don't want to know indeed, but it's the usual story with legacy workflows.

I think it's also a fully switched system so you are guaranteed bandwidth with no packet drops or buffering which is clearly useful for broadcast work.