Learned helplessness. No one ever forced her to act, of her own volition, on anything. Fatass as a kid? They took her to WW. Adult? Krystle's parent gave her an allowance to pal around with their kid, controlled the food, she lost weight. After that? No one to make the rules and force her to comply in one way or another. She simply is never going to do this one her own, because the narc/sociopath part of her is not a responsibility situation type deal thing. It's easier to live in the fantasy that nothing is under her control: not losing weight, mot avoid haydurs by disabling comments or just not fucking reading them. Not sticking to an upload schedule or any diet because "muh mentalz", which are mostly bullshit, but which she also won't take responsibility for by going to therapy (also, ironically, because of the NPD).
I will admit I'm amused by the well-meaning noobs who come in and earnestly talk about Big Al getting better if she would be x, y, and z, apparently not understanding that's like the informercials at 2 AM for the same products, over and over. Nothing changes. Big Al will not change. Ever.