One is "well, no troll could have enlisted separate Amazon CSRs to tell authors their books were delisted for being adult in nature". Setting the (tenuous at best) possibility of social engineering aside for a moment, it's also possible that the Amazon CSRs in question were too lazy to investigate the complaints and sent canned responses because they were sure they knew what happened. Hell, for all we know, that's part of Amazon policy -- send a canned response based on best guess first, then if the person insists they're a special case, investigate. Because honestly, anyone who's worked customer service in their life will know that most of the time, the canned-response-based-on-best-guess will almost always be the correct (and sufficient) answer.
The other argument is that Amazon uses category metadata to filter rankings, but this is speculation -- "I looked up 40 books and the results support my theory" is not very conclusive when we're talking about thousands of books. The author of the post does not claim to relay facts, but I've seen people linking to the post as "undeniable proof". It isn't. The practice of filtering by metadata has neither been confirmed nor denied by Amazon, so we can only speculate.
I would be really annoyed if this were a troll, because of how upset it makes me -- nobody wants to be told that they were/are upset for no real reason, especially when the upsetting thing is personally hurtful. Like, I read one article about this, and it cited some lady saying "I'm a heterosexual adult female and I'm very upset by this" and I was like, "o.O;; no, really? Try being GLBT, cupcake." Then I realised that "I'm heterosexual" is not meant to be offensive in this context, but is instead supposed to carry extra weight, as in, "look, you didn't just upset the gays! You also upset the heterosexuals!" And the fact that this is supposed to somehow make the argument more potent? It hurts. I don't know how else to say it.
And if the reason behind all this is an epic troll, it would cheapen, if not all-out invalidate, the anger and hurt. So I can definitely understand not wanting to believe it wasn't corporate shenanigans but rather the actions of a bored 20something white male with aspirations to hackerdom. But not wanting to believe something and refusing to believe it are different things. In general, I am so very tired of constantly redefining where I draw the line in believing things I read on the Internet. *grump*