why did so many of them decide to pack up and leave the community altogether?
Some of them never had bitcoins.
But the others already understand what Oscar Wilde said:
There are only two tragedies in life: one is not getting what one wants, and the other is getting it.
Some of them commited suicide as many ppl who won in lotteries. And BTC was kind a winning lottery for most.
Surely they did not leave altogether but everyone for himself. Btw. if it is about money, there is no community. People can realize it after they make themoney not with gradual work but with one lucky or brilliant shot.
Community lives from joined hopes of (poor) people that some day, they will do together something...
But once it is reached, the people realize that fulfilled dream is like sex from last year & castration all in one. Dream is life, life is dream, challenge is gone, there is no shared dream, so community and even personality has huge problems.
What is left is gambling and not community then. Gambling is at least temporary relief from the emptiness of the life.
When you have no money and you want them, you have many co-fighters in this world. There is no need to talk about it, but the shared goal to make money and to do something is the human glue. But last thing you want, after you fulfill the stupid dream, is to talk with other newbies about their dreams and see them either failing or succeeding, which is both horrible.
So it makes sense that they gamble, fuck some expensive whores or do some coke. The rest I believe work, which is maybe a bit less destructive.