Not the farmers; the producers, distributors, and everything on the way to the consumer. Research labs and marketing agencies construct fads and push it through their magazines and media IP.
I grew up in beef and dairy country in the western US. I remember dairy farmers talking about this as it was happening. It was a revenue stream from what was a waste product they often dumped in rivers.
Not saying all the others didn't play a huge part, but dairy farmers pushed for it big time.