I guess the definition of "bushcraft" knife depends on how you intend to go about it.
If you follow the "I'm only taking one knife" philosophy, I'd personally go with a large tool. I say tool because I'd rather have a kukri or a hatchet than even a large knife. And no, it's not that hard to prep small game or fish with a hatchet or kuk. Want to build shelter fast? A 4" knife isn't going to do it. Note the operative word was fast.
But. . .unless it is a military situation, or a downed pilot, or something where your primary duties preclude having more than one knife, why do you only have one? Even in those situations, I'd bet most guys will have a pocket knife in addition to whatever other "survival" or "bushcraft" knife they carry.
I'm sure I'm prejudiced based on my personal experiences and time in scouts. First thing we learned to use was the small knife, a folder, most of the time it was the BSA knife made by Case, and you were one of "the boys" if you had a Buck 110. Next thing they taught us to use was the hatchet. We were taught to split (including, but not limited to batoning), notch and made fuzz sticks with the hatchet, not the knife. Only then did we go to the medium sized fixed blade "bushcraft" knife (Often a Buck Vanguard, which is still a good choice). For most uses it DID become the "go to" knife, but the hatchet was still the "go to" tool for splitting, notching and most other heavy use.
No, we would not be without it because it was on your belt, not in your pack. An axe got lashed to the pack, the hatchet and fixed blade rode on your belt, the folder in your pocket, or on the belt in the case of the Buck 110.
So really, I guess you'd say I think the "Nessmuk trio" is more the way I lean.
In short, both sides of the argument are valid, depending on which way you're approaching the problem.