A "master" of a craft is a well trained professional with a following of clientele behind them. Masters of painting could refer to Da Vinci or Michelangelo because of the fact that that's what they were paid to do. That is what provided their "bread in their jars." They were usually commissioned by the Church, and were paid for their talents and usually that's how their popularity spread. The idea of being trained in one area of artistry, whether it be painting or sculpture or whatever medium you chose, seems to be a bore to people these days. They want people with the talent to produce alot of pieces in different mediums. The Bauhaus is an excellent example of creative and intellectual people finding a common ground in creative prospects. These students were not "masters" of a particular style, but they had common knowledge and common studies of many different styles and many different mediums.
Now it is all about the money. Not like it was in the past. Whatever is popular at the time, is what ignorant people will pay for..... to look good. Whatever is "in", they will buy, at a price. It seems that popularity has over-run the artists that actually have trained and studied in areas and whatever some celebrity at that time say's is "in" then that's what should be bought.