The cynic in me says it's less profitable, to which the logical part of me says "how is being able to give people sugar pills rather than synthesizing complex molecules less profitable?" I think the simple answer is because figuring out how to exploit that is hard. It will take many manyears of work and runs the risk of alienating a large portion of one's peers depending on what you find (look at what happened to Einstein at first). However, the benefits will likely go beyond exploitation of the placebo effect and into the very heart of how our bodies work (and it might be that we won't be able to figure it out until we open up the black box between our ears).