This is a rather odd criticism. For both philosophical and utilitarian reasons, libertarians are presumptively strongly opposed to any government regulation of the private sector. It naturally follows that libertarians presumptively oppose restrictions on private sector discrimination. It’s hardly an indication of racial animus, or even insensitivity, for libertarians to enunciate the exact same position on antidiscrimination laws that they take in all other contexts. Libertarians believe in equal rights for everyone.