OTOH some people need the psychologist because they aren't living with their parents. :\ Saying "an edge case exists" sounds really helpful to push your viewp

OTOH some people need the psychologist because they aren't living with their parents. :\ Saying "an edge case exists" sounds really helpful to push your viewpoint but if you can just put "not" in the sentence and it's still just as true... what've we gained in the conversation by saying it?