I disagree with your assumptions that most JW's lead a double life. Sure, there are some that do - mostly youths - but in the congregation where I grew up and surrounding congregations the vast majority were good people and upstanding citizens of the community.
To label all JW's as living double lives is just as bad as saying all black people commit crimes, all white people hate blacks and all wife beaters ride Harleys and hang out in bars. Stereo types drive me crazy and stereo typing JW's is no different.
Most JW's have problems and they are all human. Perhaps you witnessed heavy drinking because this was a product of mind control and a way of rebelling. And 99% of the time a JW living a double life gets caught and corrected.
I am not defending such as actions, but why is a JW misbehaving any different than your next door neighbor misnaming? None. Unfortunately, JW's have to hide when they are a normal human and see a rated R movie. They are a result of the organization and their actions are not always necessarily fault of their own. The puritan attitude is a learned response to a highly controlled environment. Don't be too harsh, we were all there once.
Do some JW's drink? Yes - and so do non-JW's. Do most JW's have good respectful manners? Yes - and most non-JW's do not - at least where I was from. Been to your local grocery store lately or drive in heavy traffic lately? I guess not. And those JW's who are rude are usually very inactive and are leading a double life - making them about as much as a non-JW as the next guy. When I think JW - I think of the old faithful -serving spotless years in dedication to their beliefs. I know - I was raised by two of them. To deny JW's are good people is crazy. Look at the way they act, the way their homes look, the way they live their lives? To say all witnesses drink heavy is ridiculous.Just about everybody I work with drinks heavily, and non of THEM are JW's.
I would say the biggest bone I have to pick with JW's is their judgmental attitudes - which again is a learned response to their controlling environment - something that is pounded in them to be. It is only a select few that break away from this vicious cycle and learn to be forgiving. But the JW belief system is not based upon forgiveness. Look at You Know and Fred (fake JW's as it may be) they are prime examples. Judgmental.
But - you are what you eat - or so the expression goes.