Whoa, hold on... I think medicine and biotech are misunderstood here.
First of all, Big Pharma != Academia or biotech startups. The former group concentrates on profitability and marketable drugs, whereas the latter two do the heavy lifting for a broad spectrum of diseases.
Secondly (and more importantly), we must realize that there are two issues at hand: the ease of developing an effective drug to combat a particular disease state, and the predominance of a given disease in the general population.
Big Pharma already claimed the "low hanging" fruit decades ago. Many of today's medical problems require a systems engineering methodology to approach them as the pathways and metabolomics are just too incredibly complicated to yield direct solutions. The search spaces are vast, multidimensional, and tedious.
To make matters worse, it's really difficult to commit to studying an orphan disease. A solution to a particular type of cancer, Alzheimer's, or HIV would have wide applicability and save many lives. Finding a solution to a rare genetic disorder, however, may help only a few thousand individuals. It's incredibly sad that there is such suffering from rare diseases, but we have so little mental capital to invest in fixing these problems. At present, biotech and medicine is nothing like programming where iteration and debugging yield fast results. Years of personal labor can become pointless if mistakes are made.
I don't know if it's justified for me to feel this way, but I wish more of the brilliant minds in programming would switch to a biotech/research profession. Computing is such a well-traversed and developed field and solution space. While it isn't glamorous, medicine and biotech really need you...