if the investigators checked with sociologists and psychologists they would find that new religious movements and cults do attract lots of people who do have mental illnesses
Source?
So for a new religious movement to tell its followers have nothing to do with apostates as they are mentally ill/mentally diseased they cannot be held responsible for inciting hatred if it is the case that there is mental illness involved.
"new religious movements" sporting largely high school educated priests (elders, COs) can now diagnose diseases?
What you've done throughout your entire reply is use straw-man arguments, which is a type of logical fallacy.
The Watchtower (aka JW [dot] bOrg) ---and other religions like it-- simply want the people on the inside to stay isolated and ignorant. It has nothing to do with former members being the problem. Watchtower treats former members the same way an abusive spouse treats their victims: they (watchtower) never do anything wrong. It's always the victim(s) who are at fault for everything.
Of course the watchtower isn't using deceptive tactics. After all, it's impossible for them to lie, because they are Jehovah.