John Ritter never got any respect when he was alive. Here is a prime example of that.

As it so happens, Hooperman was cancelled because the excellent cop show had great cinematography and John Ritter singing to a cranky dog named Bijou. Then the weasels at ABC said, "Your numbers aren't high enough to renew you nor are they low enough for us to step up and cancel you, so we are going to sabotage your show by making it video instead of film." (This is not actually how that conversation went. I am paraphrasing.)

John Ritter had the self-respect and integrity to decline being set-up for failure. That can be hard when you are the star of the show.