"There are two novels that can change a bookish fourteen-year old's life: The Lord of the Rings and Atlas Shrugged. One is a childish fantasy that often engenders a lifelong obsession with its unbelievable heroes, leading to an emotionally stunted, socially crippled adulthood, unable to deal with the real world. The other, of course, involves orcs."
Note that most people who aren't fans of Atlas Shrugged resort to making dumb, belittling jokes about it rather than articulating an argument. The internet is full of parodies, etc., but there really aren't many people who dislike the book and are also capable of persuasively arguing against it without resorting to religious authority or mocking sneers (or both). Why? Probably because most people haven't read the boo…
I have found some obscure philosophical arguments that seemed to be based on a misunderstanding or different interpretation, or making a mountain out of what I think is a molehill. But those are in the minority.
Almost all the criticism I've found seems to take a very shallow, "soundbite" perspective. eg: to presume that the book opposes charity, advocates meanness or evil, etc.
Near as I can tell, there is a huge cult who hates Ayn Rand and Atlas Shrugged, and the reason seems to be that her book clearly and logically demolishes the philosophy they espouse.
They cannot address it honestly because that would bring up the actual issues in their philosophy and likely many people would see that Atlas Shrugged shows them to be fallacious.
So, instead, they attack her with ad hominem and derision and refuse to be honest about what the book actually said.