One of them is that because it was a fringe movement, it never attracted a serious empirical base, so it has vegetarians, Buddhists, people who practice yoga, acupuncturists, holistic medics. But it never attracted much in the way of empirical science. The second is, I don't think psychology is a corner of the health movement in any sense. I think psychology is much larger than curing mental illness or curing diseases. The wellness movement narrows the domain of psychology and paints it into a corner.
Psychology is much larger than a corner of the health care system.
There are three pillars of positive psychology. Past is well-being, contentment, and satisfaction. Present is happiness, ecstasy, and the sensual pleasures. And Future is optimism and hope. That's all one pillar of positive psychology.