There are twisted people in the world, a lot of people here are going from the assumption that people cannot be malicious in their motives.
I don't think that out-and-out fakers are common, but they do exist.
Think of school bullies. You know how some of them really get off on picking on people they consider weak? A place like this would be an amazing find for someone like that.
I've known one sexual predator to claim to be autistic in order to gain access to autistic teens and children online. (Not that there are no autistic people who do that too -- autistic people are not exempt from the various human evils -- but this person was not autistic.)
I've known a different sexual predator to claim to have multiple personalities in order to get into communities where people were survivors of sexual abuse, meet the women there in real life, and attempt to harm people they considered vulnerable.
I've known people who liked to mess with people's heads, who found a whole community of people with literal language to be irresistable targets.
There are people out there who think like this, enough to fake being autistic in order to gain further access to autistic people. Seriously. I've encountered several. Not a lot, not anywhere near the majority of the community, not even a large minority, but enough to cause trouble. They exist.
_________________
"In my world it's a place of patterns and feel. In my world it's a haven for what is real. It's my world, nobody can steal it, but people like me, we live in the shadows." -Donna Williams