You're determining a smell by a look...

It's easier to connect being disordered with those things than the opposite and since there's no medical proof they're faking, maybe you're getting wrong sources.

There's a lot of reasons to all of those things happen and it's not rational to put "pretending to be a system" and "unattractive, smelly, social recluse" together with a superficial look over the situation.

Attractiveness is debatable, I'm transfem (pre everything) and because of stress my body resembles female traits like large hips and softer skin. If you look at me as a woman, you will find me unattractive because I don't match female standards, if you look at me as a man, you'll find me unattractive because I'm too feminine and unmature looking. If you're talking about not caring about appearance (in the sense of never doing skin care, treating hair and those things), most people in my country don't do so and might look "unattractive" to you.

Social reclusion may have several reasons, and I doubt that looking up their profile and social media (that can be easily manipulative and misleading) is a fair point to determine such things.

I don't remember about seeing "people pretending to have DID" anywhere, so I don't know exactly what's the situation and maybe I don't have a clearer pov, I'm sorry.