That is so sad. But from what I understand, it's not an uncommon situation with rescues run by individuals. People start rescues out of love, but sometimes they just can't say "no" when somebody shows up with an animal. Eventually they end up with more pets than they can handle, and they end up like this.
I know there's a cat rescue in my town (a lady runs it out of her home) that's like that. My coworkers adopted a kitten from the rescue, and she said it was horrible. You entire house stank. And when she took her new kitty to the vet, it turns out it had a bunch of bacterial infections from the conditions.