Simon - I think you are on to something and have presented a decent theory about why ex-JWs seem to line up on two sides of a larger argument: To be OR Not to be a believing Christian (of whatever stripe or denomination).
Before they became Jehovah's Witnesses in the early 1950s, my parents were "christians." My mother was raised by a liberal Christian mother (Protestant denomination unknown) and a conservative and abusive father with Southern Baptist / Conservative Southern Methodist connections. While still in her early teens, Mom ran away from home and took refuge at a Catholic School for Girls. They gave her shelter and protection, so she converted to Catholicism to show her gratitude. But she never really practiced the religion other than going to mass on Easter and Christmas. My father was raised a (Southern) Baptist. Never was a church-goer and never considered himself religious beyond believing in Jesus.
They became Jehovah's Witnesses after my mother agreed to a "Bible Study" engineered by my much older half-sister. My sister became a JW right after the loss of a new baby. Where she lived in a small town in Oregon, there was a relatively large congregation of Jehovah's Witnesses. Looking for companionship and solace, my sister was easily sucked into the cult. It was she who sent a JW to our door in Los Angeles and managed to start our family's conversion from barely any religion at all to active and dedicated Jehovah's Witnesses.
When my brother and I both left the religion while in our early 20s, neither of us felt the connections to the conservative religious ties of the rest of our family - most of whom were conservative Southern Baptists. In fact, we were repelled by their hypocrisy and ignorance. Not only that, but most were very conservative, racist, and alcoholic. They offered us nothing of interest - and we had never attended their churches. We chose to "go without" rather than get sucked back into a "conventional and acceptable" religious "Bible-thumper" brain-killing lifestyle.
Since I became active in the ex-JW movement nearly ten years ago, I have seen that there are clearly two distinct paths that former JWs tend to follow. The one I prefer is a basically agnostic, non-religious, "it's all bullshit anyway" path - but still tolerant of those who prefer to believe and quote from their Bible from time to time.
At the same time, most of my closer ex-JW friends also tend to lean to agnosticism and general non-belief in the "christian" lifestyles of the majority. But I do not waste my time trying to convert any of the "neo-christian" ex-JWs. They can believe if they want to - I do not care. But I do get a bit irritated when they try to suck me and mine back into their "new" Christian beliefs that tend to mirror those of the Southern Baptists that I came to detest as I grew older.
Simon - you are definitely correct to point out the major chasm that seems to have been created between ex-JWs who have reembraced conservative Christianity and those of us who have chosen to leave all of that behind and unload that burden from our lives.
I think the major difference between us is that the "believers" among ex-JWs somehow feel they should make their rehoned beliefs public and judge all other ex-JWs based on whether they believe or not. They want to criticize those of us who do not believe and judge our worth based mainly on whether we have "God and Jesus" in our lives. Those of us who have chosen the non-believer path frankly don't care what they believe because we know deep down that they are really no different than they were as JWs - they've just changed brands.
JV