This is a very interesting comment to me. I think I'm in agreement.
I think of it in a slightly different way, but I suspect it means the same (tell me if you agree): I like a choil that sits well back into the handle, rather than a choil that takes up a lot of blade. Look at the GB1 or the Military or the Rescue or the Kapara, they all have the choil well into the handle. The Watu is sort of a variation on the theme. These designs allow "meat beneath the index finger." It also means longer edge per size of knife. (Is this possible only with larger knives? But the Para has a bit of choil-into-handle so I guess not.)