With a TV call you can go long stretches where you let the visuals tell the story with no talking backing it up. That, obviously, doesn't work for radio. Also, on radio the first rule is 'mention the score every 2 minutes' as people are popping in and out of the broadcast especially in their cars. That, obviously, doesn't happen on tv (there's a score bug for that). Another issue is hearing an analysts say things like "as you can see here' or 'watch this' as they talk over replays. No good for radio. This is just a couple of reasons why TV simulcasts always sound 'off' on radio and can be frustrating for the person listening.