I agree the behavior is counterproductive. It's unsettling and unlikely to sway public opinion against the Watchtower.
However, I'm a lot more sympathetic than I used to be. No one would be taken seriously if they said "Boy, a lot of those victims of Bernie Madoff's pyramid scheme come across as crazed psychopaths."
A great many ex-JWs are dealing with significant psychological damage from the effects of feeling like they've devoted their lives to a religious cult. No two people are the same. Some people are able to walk away relatively unharmed. Others have significant trauma and are never able to fully recover.
Looking back, I was borderline suicidal for many months after I wised up to the "the truth." Twelve years later I still have lingering issues I'm dealing with, but I woke up in my mid 20s and have been able to more or less remake my life.
Having a fair number of "crazies" lash out is to be expected from a group of people who used to belong to a religious cult.