Steven,
I think you mention the most important factor in becoming a "famous" tier. Of course it presumes that the tier is an excellent tier and also that the tier can improvise new and different patterns. But, I have seen a lot of tiers on this forum who could probably be a "famous" tier if there were media attention of them.
Perhaps the best example is Jack Dennis of Jackson Hole, WY (actually Jackson, Wy). He was a fly tier and local guide as a young fellow. Then, "The American Sportsman" happened along and needed a local guide to take the star on a fishing trip on the Snake River. Somehow, Jack Dennis was assigned the task. He got along famously with Curt Gowdy. It put Dennis on the path to being famous. Then, he wrote a book on tying western flies and the rest is history.