As an admirer of Ayn Rand and supporter of her philosophy for nearly 50 years, I can say with authority that very few people who criticize her have any deep knowledge of her thought. An all-encompassing philosophy needs to be complex, so learning it is no easy matter, especially considering how much of our childhood upbringings must be overcome. So fully understanding Objectivism requires reading and understanding at least half a dozen or so of her books. Her critics typically have read one or two and have been scared off by the challenge to be rational, leading to the bromide that Ayn Rand is a phase that the young grow out of. I and thousands of others are proud to prove otherwise.
(So some of you may wish to attack me personally without knowing any more about me than what I’ve said above. Just remember that ad hominem attacks are an admission that you don’t have any better answer.)