Comparing Mammals, fish and reptiles hardly argues the point validly IMO. Their needs are vastly different. Their metabolisms are completely different.
If a baby mammal, rodent or fish doesn't eat within a certain time after birth, it will die. I've had new born Boas (1 actually) that went it's first 2½ months without eating, and this is without getting the benefit of yolk absorption. And I bet they can go even longer and still end up thriving.
The animal mentioned above was fed every couple weeks for 3 months after finally deciding to eat, then went to 3 week intervals just like the rest. She seems to be thriving too, even if she is smaller then most 3 yr olds I've seen, and is not any smaller then her litter mates that ate right away, and 4-5 extra meals.
I see what you are saying. But to me, just because something can go a period of time without anything, doesn't mean it should. And that's just my opinion. I know that a snake can go VERY long periods without food. I've seen a bp go 7 months without food and still be perfectly fine. I guess I just don't really agree with feeding something that's in my eyes a baby less often than once every 14 days. I do agree that as it gets older, less often feeding are vital to maintaining healthy weights, because just like anything, with age the metabolism slows down.