The LACK of Love.
Unless you were "popular" you didn't get any help.
If you missed a few meetings due to work or sickness, you were considered spiritually weak.
Before I was baptized in 1991, (I was 19 years old) I was surrounded with JW's who wanted to go out to eat, hang out, etc. After I was baptized it all stopped. I asked a friend about this who had also come into the "truth" at the same time, getting baptized on the same day and his opinion was that "The witnesses were withdrawing so as to see if you were really serious or not, a testing perhaps?" My reply was "If we weren't ready, then God wouldn't have allowed us to be baptized." He agreed. Years later I found out that by spending time with an unbaptized publisher any JW could count it as FS time. I thought they wanted to be friends and was greatly hurt to learn all I was to them was some time counted on their FS slip.
I barely had any "friends" my age, although there were plenty in the KH my age. I wasn't pioneering (my family had turned me out for becoming a JW) and I was learning to live on my own for the first time. I was devastated but I stuck it out. I hoped that eventually I could pioneer and support myself, but it was very hard being single and having no support from my family or the "friends".
Most of my associates ended up being "older ones" or one particular Elder. He wasn't born in and had a pool table in his attic, where we often shot pool and talked until late at night. If I hadn't had him as a friend I would most likely have left sooner.
People being judgemental of others. If you weren't a pioneer or a MS, you were garbage. I recall hearing two young brothers (born-ins) who were collecting FS slips and one of them remarked about the time on one of the slips. He said "This person has less than 10 hours this month. Why do they even bother?" That pissed me off considering the two brothers Dads were Elders and supported them so that they could pioneer. They were both under 21 and quite arrogant. I wanted to wring their necks and point out that not everyone had their situations and they were doing the best they could.
I recall being interested in one particular sister and I spoke to her Father. He said I needed to go out in FS more, comment more (I commented at every WT study at least 3 times in a meeting, I gave talks in the 2nd school, handled the mics and led the FS group when there wasn't an Elder or MS present). I also had gotten on my feet financially. I just wasn't pioneering and that's what he wanted as his daughter was a pioneer and had her own cleaning business (but she lived at home, whereas I did not).
I finally realized it didn't matter what I did. No matter how hard I worked if I wasn't a pioneer, I was no better than something a JW would scrape off their shoes.
Those things, more than scripture was why I left.