No doubt Evans, it would've been a problem back then. The difference then and even in the 80's/early 90's to now is... there wasn't that much choice. Once the show got on the air, a lot of people even those who might not have been "into" Trek watched it because it's what was on. They liked it, but weren't avid fans.
Today those people that might like it, but aren't overly into it, can find -their- niche given every cable package these days comes with at bare minimum a 100 channels. That's where the widening gap comes into play and why I think cbs is reluctant to throw a lot of cash at a new Trek show. Money does change minds, and if you happen to have ten figures to invest in a highly questionable project or know someone who does, by all means sir, go for it. I'll watch.
As for the shorter British style season... I dunno David. If you're shelling out for all those expensive sets, props and what not I can't see the show wanting to rock the boat with that one and not get the maximum yield for their investment with a longer season when you know the cancellation talks are going to be there from the get go.