Some people just do not understand. Give them ginseng and they think it's a carrot. Feed them ghee and they think it's lard. Of course they benefit even if they do not understand, but not as much as they would if they knew what they were doing, and why they were doing it.

Buddhism says that all sentient beings are equal. However, at any time only some people have karmic affinity with Buddhadharma. Those beings with karmic affinity encounter the Dharma, appreciate it, understand it, and benefit immensely. But you cannot force someone to understand what he or she reads, and you cannot coerce anyone into practicing. Although all sentient beings are equal, some receive more benefit from Buddhadharma than others.