Perhaps they do. I was trained from the age of about 3through university to hear those beats and associate them with playing the wrong note, or at least an off key note, so I doubt that I would feel the same things. It would probably make me agitated and irritated rather than sleepy. I don't listen to sounds with the same sections of my brain as people with no musical training ( or training in a different scale system). That's not better, just different. Just like people who learn a language from birth use a different section of their brain to process that language from people who learn the same language as adults. Not better, just different.
So it doesn't surprise me that it works for many people. I fall asleep with the TV on. So we're different. Good! Life would be dull if everyone were the same.