I think the very idea of a "master" framebuilder is a bit silly. Sure there are certain skills involved in building a frame, but as someone said it's no more and no less than accurate joining of metal tube together. Anyone could, with tuition, build a frame without any previous experience. There's no magic or mystery involved.
As long as the frame has mechanically good joints and the geometry is suitable for the rider and purpose, then I don't it matters who built the frame, as far as riding qualities are concerned.
Certain builders become more well known because people write about them. Also, some of the most sought after frames are not even built by one person but come off a production line or are built by several people.
Sorry, that's plain silly. It's like saying that playing the piano is simple, all you have to do is tap the keys.
The really good builders in my view mixed and matched tube sets to fit the customer's needs, and often flew in the face of fashion. These engineering-led builders were the real cream, for example Tony Oliver.
Ride it or milk it!