Like the time period in which this happens, but the two biggest drawbacks are the acting and the script. Characters tend to be one dimensional, due mostly to the script, and unfortunately most of the actors seem to be content to portray them as such. Lead characters do stupid things, like not terminating their enemies when given the opportunity. This of course happens so enemies can show up later, which of course makes the script writer's job easier they can recycle characters throughout the show.