People are interested in all sorts of things - fictional and nonfictional. They are interested in and discuss many things from Game of Thrones to quantum physics.
JWdom affected some of us greatly; for some of us, it was our lives for decades. Some of us were extremely negatively affected by it. I think it's natural for one to be interested in something that played such a big role in his life. Hell, I'm still interested in the goings-on at my old high school.
In addition, the JWdom situation is real life. Observing the goings-on in JW land is a study in human nature, psychology, sociology, law, justice, religion, etc.
Also, I hate deception, phoniness, stupidity, self-righteousness, condescension, lies, corruption, unreasonableness, etc, and such abound in JW land. I have a strong sense of justice, and I love to see justice administered. I am eager to see it weaken and to see the reactions of the org as a whole and individual JWs.
And one more thing... the cult still has all my family members except my wife. The fact that some of us still have family in is further reason to be interested.