I think the question should be; What did they know about survival knives that we don't?
It's a lot easier to open a coconut with a forward-weighted blade, and that's important because you can't make haupia without coconut milk. ;D
I have the suspicion that in the original cultural context these blades are not regarded as "survival knives," which to us is somehow a special category. They are probably just tools people use regularly, and if you go into the jungle or the woods, you carry the one you normally use for chopping, because you might have to do some chopping there. It wouldn't be unimaginable to carry a smaller knife also, for the more delicate tasks. Alternatively, one could try to make do with the big knife and throw delicacy to the four winds.
A caveat: my familiarity with the original cultural contexts usually involves fruit vendor grannies using the sort of big knife we're talking about to open fruits for me.
A thought: maybe this is environment-dependent? In tropical areas, there are more vines and soft branches, which a machete-like instrument can chop. In northern woodlands, however, you may prefer a hatchet/knife pair.
Can you cut soft hanging vine with a hatchet? Maybe that's a problem.