many people in this forum might think differently, but I will illustrate what i have had experienced in Coffee world.
Barista + Roaster + Cupper (catador in spanish) + Exporting coffee/company personals... all intersect one way or another. THEY ALL BENEFIT FROM EACH OTHER AND SOMETIMES IT BECOMES "ONE".
example : Raul Rodas.
Raúl Rodas World Barista Champion!
he was a world barista champion 2012. I met him last year at his company, trying to recruit into our company. after he became world champion, he decided to make his own brands of coffee and started selling in Guatemala and overseas. He was studying to be a great roaster and still studying and perfecting. He told me that Being a Great Barista really helped him to understand about roasting better than other people. Now he roast and sell them with his own brands, all around the world.
Hanna Teramoto
New Zealand Specialty Coffee Association
she became a New Zealand Barista Champion working for a small retail coffee shop. Now, after winning the barista contest, she got hired by bigger and more well known coffee importing company in NZ to be a buyer and also to be a cupper.
Hector Gonzalez
Hector Gonzalez
2010 world cup taster champion. he also started his career as barista and roaster. and then, got a job at Olam and finally became one of the best cuppers in the world. He is currently one of our partner for our company. and still works part time at Olam as main cupper.
Eric Gonzalez
he is our Roaster / jr. cupper for our company. he started as Barista for & Coffee (yes, the company and brand name is "&" cafe. second largest coffee chain store in Guatemala) and then went on to AnaCafe and eventually became an instructor of Barista and Roaster at AnaCafe for five years. Now he does roasting and cupping for our company. and assists in exporting coffees to overseas.
My main point is that EVERYTHING INTERSECTS. Every job you have in coffee industry benefits the others. In order to understand how to roast well, you must understand about the beans, characteristics...which leads to be cupper. If you are great Barista / Roaster / Cupper and have an ambition and goal, probably, he will open up his own business.
it is absolutely true that many people stays within one job (Barista / Roaster / Cupper ...etc) all their lives. However, if you ask me, if someone really want to know about "coffee", Barista will lead them into becoming a great roaster who eventually wants to have full control of his "creation". And that will also want to be a cupper. To me, it is kind of natural process in coffee industry.