Originally Posted by Kat_YYZ
Guessing it's the same reason the sports broadcasts try not to show streakers or other people who run onto the field of play to cause a disruption. They do it to get attention and if you show them, you give them what they want and encourage others to do the same.
That sounds very probable.
I've seen quite a bit of Johnny Jump, so it doesn't always work for sports broadcasts, though.