I don’t agree with your prior example of someone becoming addicted to meth. If you actually ever left the organization, then you would find you lose everyone instantly. Your friends, family, support structure, perhaps even jobs and business opportunities, you literally become one day to the next alone in the world. Now some people will react to that by doing drugs or other things including suicide.
You say, if only they adhered to JW’s standards, that wouldn’t be a problem, sure, but then you also have to accept all the other things. It is the no true Scotsman fallacy however, because as soon as anyone makes a mistake, they are no longer JW and you say they should’ve just been perfect.
People being pushed into destructive life choices because they are being shunned by their family is at least partially blamed on the same policies you say are inherently good. Even worse, the constant pressure to ‘be good’ to the extent that even normal relationships are suppressed (whether those are sexual or not) is the cause that some people react by ‘being bad’. You don’t find such moral swings in other religions, you stop going to church is rarely if ever the cause of an immense psychological swing, except in cases of severe abuse. And there is plenty of scientific evidence to back up the fact that prior persistent abuse at any age is the cause of self-harm and destructive life choices.
My opinion is that the overall morality of JW’s is lackluster and is the cause of many harms, including the idea of ‘good’ things, the emphasis on not smoking, the emphasis on not having relationships with unbelievers is the cause of many problems, it is not virtuous, because you’re not doing it for the right reasons and obviously, when those reasons disappear, so do the restrictions. If you are told your entire life, your family will abandon you and our god (the WTBTS) will judge/kill you if you do this bad thing, then if your family and god does abandon you, there are no more moral restrictions on the bad behavior.
In other religions, you are told the same thing, but not because your family will stop talking, but because God will be disappointed, but forgiveness being the key there, they actually encourage people to come forward with their issues. It is why most churches have support groups for various things from abuse to smoking to alcoholism and drug use, that is their role in society after all and is a net benefit, you will be accepted and have a road to recovery if you make a mistake. JWs will let you or even cause you to fail and then they will curb-stomp you for whatever problems you may have as a result, people that made a mistake in JW-land are often permanently marked even women and children that are abused by a husband/father often are marked ‘damaged goods’ or having been the cause of the abuse.
The fact you can find a few good pieces on a maggot infested slab of meat does not make it a good steak. You’re basically arguing that if the outcome of an action is good, the action is good, then let me give you the example of the people that go in the justice system or police because one of their family members was murdered, outcome good, therefore murder good?