I'm sorry to blow the pet theory of so many TV reviewers, but the failure of "Cop Rock" has nothing to do with the music. True, the songs are often bland, but that has never hampered musicals in the past, and in this show the songs are short enough that they are not offensive. They are also well-integrated with the storyline.
The musical convention works.
The downfall of "Cop Rock" is not the rock but the cops. By the end of the first episode of "Hill Street Blues," major characters had been clearly delineated; we knew their names and personalities. I have watched "Cop Rock" for over a month and have yet to see a character who is memorable, well-drawn or mildly interesting.