I think the concept is part of the appeal; a lot of shows had done 'western in space', but by taking out the western/settler elements (or doing weird things like in BSG:TOS).

This just put them back in as a natural element; the ACW parallels appealed to the history geek in me as well.

Hmm, Culture as a TV series. Um, yeah, so not going to happen. And even if it did, it'd be bad...