Star Trek had it's share of earth based episodes filmed on the studio back lot.
Somehow I don't think that stuff would come off as well today. The parallel Earths are probably one of the major things people think of when they think of Trek being "cheesy."
I'd like to see 'em get their butts out to the desert more often to film. We need at least one return to Vasquez Rocks. DS9
made some good use of Joshua Tree National Park. If they have the money to get out to Arizona, Utah and New Mexico, there are even better/less overexposed "alien" backdrops waiting.