In the realm of pop celebrity, the bar has been lowered so far that there is no bar. People can be famous for being famous, famous for being infamous, famous for having once been famous and, thanks largely to the Internet, famous for not being famous at all.
People of a certain age look back on the Mayberry of 'The Andy Griffith Show' and become almost as homesick for that simple fictional hamlet as they do for their own home towns.
Crime dramas will never go away as long as people turn to television for, among other things, reassurance and comfort.
Gimmicks come and go; the cop show seems one genre that will never leave - not as long as people like to sit at home in the suburbs and see what awful things go on in the cities.