I have been considering this often lately, as I know many who have for all intents and purposes, left the organization, yet they still believe it is the truth. I know when I left, it wasn't long before I had to really investigate for myself, (after a matter of about three months of just taking a "breather"), weather or not what jws taught was actually the "truth". I think, this was because I realized that SOMETHING other than just my own weakness had to be what made me "give up". As it turned out, I was right. There was, obviously much wrong with the organization, and it did not take me long to realize that it wasn't the "Truth". It was actually quite a simple process, once I did it.
That said, what keeps "inactive" ones from taking it one step further and actually doing some research on the WTS? I mean, for the peace of mind alone, the time spent is worthwhile. I don't know how someone can live with the constant nagging feeling of "I just couldn't do it, but I know I'm wrong", kinda thing. I have an "inactive" jw friend of mine, almost completely not living the "jw lifestyle", yet is very reluctant to consider the possibility that the org just might be wrong. I really don't see how someone can be content with that.
j