I'm no psychologist, nor do I play one on TV, but if I had to wager a guess, there's a bit of parasocial-ness at play. They get attached to you through your content, feel like they "know" you, and then are eventually slapped with the cold wet mackerel of reality in that the only reason you're "interacting" with them at all is because you're being paid to. At that point the switch flips and you need to be punished. Coupled with what you said about the fact that here is an actual, real live woman participating in their fetish and boom. Desperation leads to anger. Anger leads to hate, and so on.
Honestly it's one of the worst things about this industry for me. I have to keep reminding myself that models are paid to be charming, and no matter how nice/affectionate/flirtatious they are to you, you have to keep them at arm's length for everybody's sake.
One other reason models "leave" the industry that nobody mentioned is that they were never really part of it in the first place. A model can show up at your crib, shoot hours' worth of content in one go, and then never come back... and if your release schedule has you dripping out their clips on a monthly basis over the next year, it looks like she's repeatedly coming back to shoot more. For some reason it never clicks with people that models don't shoot singular, five-minute clips at a time, and that there's a reason she's wearing the same outfit in all of your videos with her.