I've been asking myself that question, since I think the tendency among conservatives to blame all our troubles on 'Marxism' is too simple-minded. Maybe we should just call the cast of mind 'scientific materialism' or 'naturalism' (in the sense used by philosophers like Thomas Nagel), but then that wouldn't communicate much to most people. The fundamental defect I think is the denial of the transcendental and the quasi-Epicurean/ Darwinian belief that Nature's order can emerge from randomness. But that doesn't quite work either since Stoics and their modern versions (Spinozists) have preexistant order that is immanent rather than transcendant. Hence the moral poverty of a humanism that recognizes no principle 'above' man and intrinsically binding on him. Any suggestions?
