A meaningless comparison, as the point of "Don't judge a book by its cover" is that prose is not a visual medium and it is therefore inappropriate to judge its quality by the visual quality of the exterior binding.
Television, on the other hand, is a visual medium, and Doctor Who is one that in particular follows a Realism/Naturalism production conceit. As such, it is incumbent upon the production team to at least attempt to make the aliens look plausibly Naturalistic and not as though they picked the costume up in the kid's section of the local Wal-Mart.
But my point is that an episode shouldn't be
just judged by the visual elements,
Of course it shouldn't. No one is arguing that quality scenic or prop designs are
sufficient conditions for a quality program. But they are
necessary conditions for a quality program.
Certainly having realistic-looking Cybermen isn't
sufficient for the program to be good. (If that were the case, all those Borg episodes on VOY wouldn't have sucked.) But it is
necessary for the program to be good.
I know you're into theater, so I have to ask: How is that kind of train thought any different from viewing a play?
It's simple: Theatre encompasses many different production conceits. Everything from Realism/Naturalism to Romanticism to Melodrama to Expressionism to Absurdism to Epic Theatre to what-have-you.
The vast majority of television programs, however, adhere to one specific production conceit -- Realism/Naturalism. The modern
Doctor Who is amongst those programs. When we see Rose's flat, we see a detailed set that aims to re-create what real-life apartments look like for the screen. When we see a corporate office, we see sets designed to replicate the designs of real corporate offices. When we see characters from the modern era, they are dressed to imitate the manner in which modern people dress; when we see characters from the past, they are dressed to imitate the manner in which people from that era dressed. Etc.
Doctor Who, like most television sci-fi programs, also tries to apply this principle to its fantastic elements -- it seeks to create the illusion that these fantastic elements are Realistic/Naturalistic. On numerous occasions, the program has tried to create the illusion that the TARDIS
really is larger on the inside than on the out. The Judoon are designed to try to make you think that they
really are aliens with physiologies similar to those of Earth rhinoceroses. When we see Adipose, the CGI characters are designed to imitate the look of actual adipose tissue.
That's why I consider it necessary for modern
Who to at least
attempt to create aliens and monsters that adhere to the Realism/Naturalism conceit -- because everything else does. If they try and fail occasionally (as it seems to have with the Slitheen), I can forgive that. But I can't forgive it if they intentionally create monsters that don't try to adhere to the Realism/Naturalism conceits they've set for the production. It should not look like something you can buy at a local store.
