Interesting thing about the Columbos is how often the murderer is sympathetic. Or at least, how often one understands the motive. But the moral code of the murder mystery says that the murderer must be caught and punished, no matter how sympathetic. And of course one roots for Columbo no matter what.
The mysteries themselves... are you sure I haven't pontificated on this before now? Cause it feels like I have. I like the twenties-locked-roomness of them. I also love the view into the early seventies television aesthetic. The set dressing brings me no end of amusement.
ETA: omg, Edith Head speaking role in the one I'm watching now. She's making Columbo over. Well, giving him a new tie.