I still say that the INTP villain has the potential to be the best. The fact that they don't care actually helps them. You guys need to think outside the box. First of all, if an ENTP could be a villain, then an INTP villain can. They can just manage it in a sneakier way. Imagine someone like the Joker, but an introvert. Think about someone who doesn't care, or doesn't feel like it, but has the mindset of a psychopath. They won't necessarily go out of their way, but if the situation presents itself, why not? The funny thing is, nobody would suspect the INTP villain, because they know how to play the good guy game. They work in the shadows, not really following a plan, but doing bad things whenever they feel like it. The INTP villain is the ultimate con artist, just with murder. Sure, an INTP villain will never take over the world, but I believe that the most dangerous villains are the ones that don't have a set goal, the ones that just do things in a random manner, without sticking their neck out too far. The irony is you would never have a story because the INTP villain would win by default...the hero never knows he exists. So from a narrative perspective, yes you're right, but in theory, they really are the best villains...you can't even make a story out of them.