Why are the anonymous JW's we sometimes see on the Internet so testy with former members of their religion? They have heard the Bible verse that they should give respectful answers to those that demand a reason for the hope in them. After pondering this a while, here is my best assessment.
The Jehovah's Witness organization is like a club. There are popular members, and there are "unfit vessels". Some are selfish, some are giving. On special occasions they will band together and be unusually kind. This is not unlike many other clubs.
No matter their standing or popularity among fellow JW's, they all are united in the belief that "Jehovah" supports the Watchtower organization, and that they must stay in this club to survive Armageddon. (You're either in or out - there's no in-between.)
Unlike many Western religions, JW's hold the narrow view that only they can be right. This view used to be common in Christendom. In the 1960's when I was a child, I heard Catholic kids and Lutheran kids say the other side was condemned because they did their worship services all wrong. Of course as a JW, I knew ALL those kids were wrong because they didn't go preaching the kingdom like I did.
The world changed, and more people came to accept the idea that those in other religions might be sincere and faithful. This ecumenical movement led to better co-existence between some religions (not all). Only the really radical religions or unorthodox fringe groups held to the view that only they were doing God's will.
The world changed, but the JW's didn't. After the shakeup/witch hunt at Brooklyn Bethel around 1980, Watchtower leadership tightened the screws and created a more insular "us against the world" mood that seeped down through all layers of people in the organization. They expanded the shunning rules to include former members who merely wanted to leave without the door hitting them in the butt. The organization began demanding more and more of its members, all the while telling them that they should feel privileged to be in the "most loving" organization and "only brotherhood".
It is no wonder that some JW's are so surly when they come across former members here and elsewhere on the Internet. This attitude comes from insecurity fostered by the demands of the organization, along with maybe not being in the popular group in their congregation.
So be understanding to those in the Jehovah club, if you come across one. They're taking a beating, and whether or not they acknowledge it - your refusal to agree with them adds to their frustration and sense of unworthiness.
I don't miss being in the Jehovah club.