Khrushchev, Beria, Yezhov, etc. It really feels like they didn’t do much quality control, if at all. I know Stalin was, contrary to popular belief, quite trusting. Especially in regards to Bukharin and the likes. But it’s not like he had the power to really kill anyone he wanted, again contrary to popular belief, even if he wanted to (at least any politburo members), so his personal views of his colleagues don’t matter.
I would add the “grass is always greener” effect and the strength of Western propaganda. Easy to become disillusioned when your point of comparison is the story the West tells about itself, not the real thing. I’m reminded of all those posts on RedNote today where Chinese citizens are shocked when they hear “yes it’s actually that bad” from Americans.
Banning tiktok long enough for a large portion to join and enjoy Xiaohongshu was the biggest mistake the US government made. I know that there’s a LOT of people who are still asleep at the wheel but I definitely saw a TON of centrist or progressive Dems, and a handful of independents, suddenly realize that they were right that the government has been lying to them on many things and China wasn’t on their bingo card.