Who is supposed to provide a credible answer to this (ridiculous question)?
The question is not ridiculous at all. Certainly, the classification of "Chassidish" people is too broad and would need to be narrowed down, but the concept of people from different places with different languages having a lisp in a different language is common. Lisps are hereditary in some cases. It is a perfectly valid question to ask if a certain culture or group that comes from a certain place is more prone to having a lisp than the general population.
Within Chabad families, you can sometimes guess where a person's family stems from based on their type of lisp.