Copied from the other thread as I think it is critical to the issue.
I suspect this is the heart of the disagreement. A blacksmith is using his craft skill for the majority of the time. I think we all rather intuitively understand that. It looks like magi and MT isn't quite as intuitive.
I see the mage as working mostly with Arts. Some MT of course but more as a tool not as the real skill. To bring an example from my days as an academic researcher - I used statistic and advanced math as tools to help me but the ability that I was really using to do productive work was materials science (or some more focused skill but that gets the idea).