No, what he is saying is that when you're sleeping in your bed, you are in a situation that are far less risky than being out on the street, driving your car, etc. How many people, statistically, die in their sleep, compared to "out on the streets" (especially when it is dark)?
I'm not saying the idea is correct, but your argument is sorely lacking in plausibility - creatures with complex nervous systems get bored staying still unless they lose consciousness (and actually, we spend a lot of sleep with our brains still active in dream-world). If evolution "wanted" to come up with a way to keep animals out of trouble for the part of the day they'd be vulnerable, sleep might be a reasonable and generic way of doing so
I don't think that being asleep is safer than being awake, even in the exact same place. Why do you think someone always stays awake to guard the camp?
Oh well, not like I know what the hell I'm talking about. I just thought Siegel's explanations were too cute by half. Of course we evolved to sleep, there's nothing about us that didn't evolve. But the idea that the state of being asleep makes us safer from predators, and that's the reason for the selection? Doesn't pass the smell test IMO. Could be wrong. Been wrong before.
"as Dr. Siegel put it, sleepers are less vulnerable to harm than they would be if they were out on the street late at night"
Circular reasoning. If people didn't need sleep, there'd be just as many people on the street as during the day and it wouldn't be any riskier.
"argues that sleep evolved to optimize animals’ use of time, keeping them safe and hidden when the hunting, fishing or scavenging was scarce and perhaps risky"
... so if all the animals are asleep at night, we should be awake then, right? We can just walk up and bop them on the head from behind, Halo-style. Why don't lions hunt at night if it's got anything to do with that? Moreso, why does any creature at the top of its food chain need to sleep?
It's hard to imagine any scenario when asleep humans are more safe at night than awake humans. Even if there were giant nocturnal monsters all over the place, they could just hide .. in the same place they would be so safe sleeping, say.
Very unconvincing.