Westerns ebb and tide just like vampire shows it seems.
from a Variety blog today:
As he noted during the chat, Selleck has done a lot of westerns, and that's one reason the genre hasn't made an episodic return -- other than modern versions, like FX's "Justified" -- because there's a sense that while westerns reliably draw big audiences (see miniseries like "Into the West" or "Broken Trail"), they don't appeal much to younger viewers. I'd argue it's time to test that theory, as would Selleck.
Recently the only thing with younger people in anything set in Western USA outside was the awful social-experiment-reality genre "Kid Nation"
(2007) (TV series) which was shot near the western town/set that had been recently refurbished for 3:10 to Yuma.