Be honest. How much Ayn Rand have you actually read? It's a very common strawman to pretend that Ayn Rand was promoting social darwinism. If you truly are just worried about objectivism, what is it that you have a problem with? People being shunned for harming instead of contributing?
As far as I'm concerned, her entire argument falls apart when she starts to argue that altruism is immoral. Once you remove altruism as being a virtue and argue for a society where everyone accomplishes everything solely based on their own ability, I don't see how it can be argued that you're advocating anything but social darwinism (just with a different approach).
That's not to say that there weren't some useful things that were said, but in my life it offers very little value and none of the juicy parts are original.
As for why it makes me worry: the ones who often cite her as an influence and publicly sing her praises are very often the ones who are so off the mark in understanding what she actually said.
I cannot launch an in-depth criticism of, say, Finnish politics because I have not studied Finnish politics in any detail.
I can give a limited criticism of Robert Greene, because I have studied a selection of his writings.