For a modern take on the problem with (see: absence of) health-care startups, see Founder of Social+Capital, Chamath Palihapitiya via YouTube.
The biggest pain point for startups in health care is cost of doing business due to regulation.
It costs at best ~$10-$50 Million, and in some cases (like new drugs) > $1 Billion, just to get the starting line.
Innovation needs to be enabled by looser regulations. The FDA is an abomination and has been since inception. As Milton Friedman pointed out nearly 50 years ago (!!), the price that we have to pay for medical treatment could cost us our lives.
As we understand our physiology better, we realize that we have all the medicine we need in food.