I don't read this as passing judgement, I read it as a frank question so have a slightly different response.
What was it for me? That I filled my life with other things (higher education), was living with a non-believer and those JWs who knew me thought I was spiritually weak anyway so quickly drifted away from me before I ever left and as a result they never kept me guilt tripped in. As part of my higher education, I moved towns. Never knew TTATT. Now my life does not exist in the WT sense so I would never consider going back - with or without TTATT.
Agree the support received in this forum is great but it's no comparison to the face to face relationships that humans thrive on (whether positively charged or negatively charged). Once you are out and have that hardened affirmation (that your choice was the right one for you to make at the time), seeing these fabulous forums is refreshingly supportive. But I dare say when you are in it, it's unknown territory! That fear factor like Simon suggests can be debilitating!