TomD
Actually I think the reason is use. There are activities were constant sharpening is more efficient than: sharpen, edge hold, edge hold, big resharpening. First there are environments where stones and oil are not a good fix, but a knife "steel" basically a rod file is more appropriate, or the soft wood jobsite where a file sharpened chisel is best; there are products like scythes that need the edge drawn out continually to extrude thin steel, sharp is not enough; and there are products like razors where the edge needs to be the same for every customer. Leather working, certain survival uses, etc... all have their own needs.

It is a woodworking, hunter/skinner, etc... bias that edge holding is god. I want to be able to get through all the edge planing for at least one project before I have to resharpen my knife, but that isn't what happens working in a meat plant. You cut every working moment. There is no end or resting point.