Ooops, back to the question:
I think the ones who grew up in the JWs and are my age are starting to realize that in another 20 years or so they are going to be scrambling with their thumbs up their butts wondering how they are going to "retire" from the workforce without having made any arrangements for pension or retirement savings.
The ones who are my parents' age, who weren't expecting to see themselves grow old in This Old System™ are disillusioned that they didn't make the kind of plans that they should have made to see them through their "golden years". I think they're also disillusioned that they gave money to the Organization™, thinking that they'd never need it because Armageddon™ was Just Around The Corner™, and they realize that they could have saved that money to look after themselves in their old age.
The ones who converted are disillusioned about the Love Bomb Bait and Switch Routine.... and over how much freaking stuff you have to do as a JW to keep on their good side.
The ones who have been in for generations seem to be disillusioned about how long it's taking for Armageddon™ to get here already. One guy I used to know - a 4th generation JW - used to say when he was a teenager that he didn't think it would happen in his lifetime, so he didn't see the point of being materially uncomfortable or denying himself the opportunity for education. His dad was the PO of the congregation, and went through the business of not planning for retirement, and was still working in his late 70s. Now this guy is an Elder™ and takes great pleasure in lording it over the congregation.
I got disillusioned and ultimately left over the lack of love - especially when I was in a position where being shown love by the people I thought were my friends could have kept me from leaving. After being ill for several months and being treated like pond scum and dog crap during that time, it would make me seethe to read those fake Experiences™ in the magazines about how the congregations look after the sick in their midst. I don't know how many times I'd read the magazine and come across one of those bullcrap experiences and end up so angry that I would rip every copy of that issue of the magazine apart with my bare hands and set them on fire in the fireplace, while I called them LIARS!! and BULL$H*TTERS!! I had to stop reading them because those things would send me on a rampage for hours.