Maybe a less efficient factory process on some blade brands more than others in the coating process.So, if the first shave (or corking for those that do it) is essentially wearing down the coating on the blades (PTFE, maybe the platinum or other exotic metal, etc.), and the blade then is "sharper" and/or "smoother" as its keen edge is now exposed, then really what is the point of putting on the coating in the first place? Marketing? Assuming the blade isn't carbon steel but stainless, the chances of it rusting (in most cases) isn't great. Or am I totally missing something here?
I've used coated blades that were good from the first go, and some that took a shave or a light run across a cork to give a smooth comfortable shave.
In the end, for me at least, the why is less important than the is. I just use blades I don't have to mess with.