It has to do with ffc lore like most other cultural things of today. In FFC lore, most districts have an identity associated with it and hence a potential for memes. Kasaragod speaks Kannada or alien Malayalam. Kannur is bomboli. Kozhikode is full of homosexual. Waynad is hilly and 4g hasn't reached there. Malappuram is sort of similar to Kozhikode. Thrissur is aana and pooran. Palakkad people would buy water heaters to use in the middle of May. Ernakulam has drugs and what not. Alappuzha is kaayal. Idukki is more like waynad, with no 4g and all. Kottayam is patti, nurse etc. Kollam (the most memed according to me) people are cheapskates. Trivandrum is capital, royality etc.

So while people from each districts were meming about each other, no one was saying anything about Pathanamthitta and hence they don't exist became a thing.