it was a good show, and a thread would pop up here every season. but the episodes were largely self contained so there wasnt ever very much to discuss about it.
honestly, though, i think asking why it was cancelled is looking at it wrong. NBC cancelled this thing after like 6 episodes. The 3-4 seasons we got on TNT were all gravy.
i liked it a lot. while police procedurals are as old as tv, most of them follow homicide cops. this show did a great job of showing the day to day life of the beat cops. they took a giant dumpn all over the fans of the show with the way they ended it, though. went from a fairly realistic show about beat cops to a stupid soap opera BS ending.