Do you think that some people simply can't cope with being outside the JWs?
Unfortunately, yes.
This 'religion' requires extraordinary investment of time and effort. Consider decades upon decades, all the while, the adherent is learning to abandon their sense of skepticism and critical thinking (if they even had such to begin with).
The WT quite intentionally renders its adherents absolutely dependent on it. I have seen relatives allow themselves to be stripped of any sense of self and self-direction. My mother wouldn't even know who she was, if she wasn't a JW.
Many (most?) of these 'lifers' are simply not equipped to embark upon a single day of life, without the imaginary 'safety net' the WT religion claims to provide.
I am currently resolving myself to give up all hope for family in the cult. I cannot pry them out if they're not ready/willing to walk out under their own power.
We have the profound benefit of living in a such a time, where all information is accessible with a few keystrokes, a modicum of courage, and the sense of integrity to NEED TO KNOW WHAT IS TRUE...despite the discomfort that may follow.
The path out of this cult is known, well-worn, and (though not without difficulty) easier to tread with each passing year.
Some will never take it, because the WT religion is successful in consuming souls.