It makes more practical and economic sense.
In modern times I view the mora as the equivalent in regards to cutting edge to steel used ratio
From a purely practical point of view I personally believe due to less weight in the handle in a puukko I prefer the overall balance of a puukko over a full tang of equal blade length,but that's personal preference on my part and i can make a puukko handle that fits my hand perfectly but o i do not have the time skill or money to make a full tang that would give me equal results