>>18567 (OP)
The original Star Trek came out in the 1960s so that explains the cowboy shit as much of TV at the time was comprised of such shows.
As for the later incarnations of Trek, the Wild West is iconic, when you see it on screen you know what it is immediately, and that's too tempting for set designers to ignore.
The best of the lot was ENT's North Star I think. If aliens abducted a bunch of people from 1800s America I can see them overthrowing their captors and eventually rebuilding a version of their old homeworld centuries later.
It's a dumb idea though, any race advanced enough to build starships could probably create dedicated droids to do tasks easier than they could train and maintain a population of alien slaves.