Two more cents...
As a knifemaker who has used steel from several different suppliers, not all steels are created equal. You can get the same grade steel from two different sources, and there can be significant differences in the chemistry and initial internal structure of the material. In a backyard shop, even though I feel comfortable heat treating 1095, 1095 from one place needs to be handled differently than 1095 from another supplier. In my experience, all steels suffer this inconsistency, even though they have the same grade label.
To think that all 440C is exactly the same, all over the world, is foolish - and why I suggest that it's not an ideal material for knives. But people like shiny and no rust, so that's what they get, and if the shop producing blades isn't paying very close attention to what they're doing, they can mess it up with no visual signal that they have.