Why The Original Cast Abstracted So Quickly
So we know Scratch and co arrived in late 1999, and Ragatha in late 2008, with probably around a 1-year period where Kinger was entirely alone (long enough to develop dissociative tendencies, but not so long that he couldn't still pull himself together for Ragatha). This means almost the entire original group didn't last more than 6 years in the circus, while characters like Ragatha have managed to last at-least a decade. I think there's some major reasons as to why that is:
1. They understood the true nature of their prison
Unlike everyone from Ragatha onwards, the original cast were all developers who understood on a deeper level what the circus was, and more importantly what THEY were. As it's been all-but-confirmed that the characters within the circus are digital mind scans with no bodies to return to, they started out understanding there was no escape and nobody was coming for them. The knowledge that they were nothing by artificial copies would have been existentially damaging, and made relinquishing their humanity all the easier.
2. They were real-world colleagues and friends
Now you'd THINK this would have been an enormous boon for their mental longevity, since they all already had bonds even before entering the circus, but I think it was actually a huge detriment. They could actually remember and remind one another of their pre-circus lives, which only reinforced how trapped they felt. Additionally, this shared experience would have made them SO tight-knit that the loss of a single member would have been emotionally devastating to the rest, likely leading to cascading abstractions.
Despite what I said above, the original cast's bonds PROBABLY would have helped in the long run... had Scratch not abstracted when Caine tried editing his mind files (presumably trying to "cure" the cognitive impairment from his brain tumour). Witnessing someone they all knew and looked up to devolve into a monster would have been awful enough, but I'd argue the true horror would have been their collective realization that there was no cure. Before the cellar protocol was introduced, they probably spent a LOT of time trying to "fix" Scratch, with the repeated failures only compounding their feelings of hopelessness. Had they been able to accept that Scratch was gone in the same way the modern cast holds a funeral for Kaufmo, they could've grieved and moved on. Instead all they could tell was that their friend trapped in a form of perpetual, violent distress, and nothing they did could pull him out of it. The grief, frustration, and hopelessness of that is likely what caused the next abstraction, which only would have made things even worse.
4. They thought they were alone
I think this is probably the largest contributor. Since they didn't know new people could enter the circus, they thought it was going to be the seven of them trapped indefinitely until someone on the outside pulled the plug. With each abstraction, that sensation of isolation would have become more and more crushing. By the time it was down to just Kinger and Queenie, even their love for one another would have struggled to stave off that kind of existential dread. I'm pretty sure Kinger lasted as long as he did on his own entirely due to self-loathing; he found purpose in forcing himself to hold on and remember everything he felt personally responsible for as Caine's primary creator. Abstraction was an escape he didn't deserve.
