What ppl are missing is that most of these writers don't know about type and might not even know an INTJ in RL (given their rarity)
They are just giving their villains exactly the traits they require to be an effective threat, which is often dilligence, smarts, an uncaring exterior.... they don't got at it with the expectation of writing 'INTJs' but 'effective villains' and it ends up looking roughly like an INTJ only by coincidence.
It could also be a sort of unconscious thing - While there are many triumphant exceptions, most artists are Perceivers, that is, Ne or Se users; So Si ('mean girl' or 'art-hating conservative dad' anyone?) and Ni would be functions they value or understand less; So maybe they might write the character based on behaviors they witnessed & didn't understand, or suppressed/less reliable shadow parts of their own psyche.
Sort of like when ppl try to think of what robots/aliens would sound like, they end up talking suspiciously like Ti users?
Ti and Ni both being rare functions. Te isn't anywhere close to odd or unapreciated, but when you consider the ubiquity of Fi dom artists, well, no one likes their inferior.