I think the point is they don't want to debate about specifics, but rather what people think of the idea of limiting rights based on mental heath diagnoses. I can see how some 'specifics' could easily lead to entire derailment of the thread and getting away from the discussion of the principle of the idea.

Should someone be denied a right other people have simply because they have a certain diagnoses? seems to be the basic question...if people want to discuss specific rights being violated and opinions in more detail there is plenty of room for other threads.