Fear of being wrong is one of the main factors that prevents people from being even halfway decent allies, they're just so overwhelmed with the fact that they may be called out for not being perfect that they don't even bother to help their fellow humans. I will freely admit that being an ally - to any group - is tough because it forces you to examine your own privilege. You are an Ally because you are a member of the privileged class who has decided to stand up for the marginalized. That means that you benefit from privilege. Even if you are a member of one marginalized group, no person exists in a vacuum. I'm an asexual, disabled woman and yeah the last part is hard for me to admit, but I'm also white and from an affluent family which makes me pretty damn privileged despite the non-hetero, disabled portion of my existence. I benefit from "benevolent sexism" all the damn time because of my whiteness and cisgendered-ness. Just because benevolent sexism is also sexist behavior, that doesn't mean I don't benefit from it.