Do I sense a new title there?
As to the topic at hand - I definitely believe that it doesn't only apply to SW / Sci-Fi creations - if anything, with Town & Trains accuracy tends to become an even greater issue because, at the end of the day, things that City / Trains creations are based on actually exist in real life and not just on movie reels... Yeah that came out wrong, but I'm not bashing SW or Sci-Fi, just bear with me!
The thing is, at the end of the day you can go for 1:1 perfection only by using LEGO and not modifying your bricks at all. Which will soon find you stuck in a terrible mess since more often than not the proper, 100% realistic proportions, can only be achieved by using scales that vary greatly from the 'regular' minifig-scale, no matter what you perceive that to be. So you either must end up creating an architecture-worthy MOC and be happy that you've managed to pull of an exact replica - or decide for yourself which are the parts you'd be willing to compromise in order to ensure that the MOC still fits the scale and comes as close to the original as possible.
For example, I don't believe that there's any way of packing all the details from an original car or train model in 6-wide. Which is why MOCcers take a representative approach - and use the respective object's strongest visual features as leads, on which they base their build. The same applies here, at least to me. As long as the MOC looks like the real (or movie-real) thing, and makes a conscious effort to deliver in terms of quality and visual aesthetics, it will surely grab my attention. Yes, of course, perfect replicas can really turn out jaw-dropping, but they require a perfect eye both for scaling and dimensions, and for detail - and I find that it is often a case of sacrificing one for the other, which is not really to my taste.