Attempting to create a show set chronologically earlier (in the eyes of the characters in the show) than the original series leads the end results to be detrimental to what the original attempted to do. With the example of Star Trek: Enterprise, I was left confused and inevitably annoyed at everything it attempted to do since it is set in the mid 22nd century and Star Trek: The Original Series is set in the 23rd century. The difficulty in keeping track of the mythological information that the original series and this series explains is mind-numbingly impossible. It feels as though the creators of this shows did not even bother watching any of the other series to try to ensure some kind of continuity with the time line already set in its place.
Going beyond that point, it feels as though science and tackling philosophical issues in the dialogue of the star trek world has apparently been left behind and in its stead has been replaced by pathetic attempts at titillating the viewer with alien sex and nudity. This of course wouldn't be shown, but sex is only weapon they've got and they are selling it in the place of what usually makes a star trek series worth watching.