^I suppose you could say that. I think the reason why UK parks seem to have quite a bit of theming for a small area is because of Tussaud's. They remind me of like a combination of Cedar Fair/nicer Six Flags parks, along with a slight Universal theming touch. I'd be really happy to see Tussaud's invest in theme parks in the United States.
I'd say that for theming, it depends where you go to see people care a lot about theming. I'd say mainly the enthusiasts that have been exposed to extensive theming tend to care about theming for parks, such as enthusiasts that live in Florida as opposed to enthusiasts that live in Ohio. Myself, I like to see some theming in a ride, too...and if a ride doesn't have theming, it should at least have some midway/queue interaction. I wouldn't say that rides cannot be good without theming, though. I think that if I were to ride Nemesis, it would be almost just as good without theming as it would with, mainly because it looks to be a pretty forceful coaster that could still entertain riders without having to jazz up the surroundings. Nitro is an example of this. After the turn into the lift, all the track is just out in the woods, with no theming (other than the trees), and no park interaction. However, it is a somewhat forceful ride with some decent airtime and a nice bit of speed, so it still does well regardless and is my #3 coaster. However, my #2 coaster; Revenge of the Mummy at USF, could not survive without it's theming, which just happens to be a dark ride. The coaster part has 2 good pops of airtime and a decent launch and some nice laterals, but if you put that ride in a field somewhere, it just wouldn't be the same.