Same reason they haven't cured cancer or AIDS or figured out a magic weight loss pill. No profit in the cure. Disease is profitable.
There's profit in a cure as well. Polio has been virtually eliminated in our country. Young people have no clue what a scourge polio was. And lets not forget small pox, tetanus, malaria, yellow fever... and that's just off the top my head.
So many like to bash the pharmaceutical company's for making a profit forgetting or, more likely, just not knowing what life was like before modern medicine. The average life expectancy just in the beginning of the last century was in the forties.
And what do you mean by "cure" anyway? My sister, along with millions of other women, had breast cancer and was "cured". It is no longer an issue in her life. Same with my mother. Magic Johnson is bigger and stronger than he was before he got AIDS and is living a full and productive life.
If by "cure" you mean a vaccine, like the polio vaccine, that eliminates a disease completely then that's another issue. And I'm going to guess you don't have even a hint of a clue of what goes on developing a vaccine and how hard the medical community works finding that cure. Anybody in that field would love to be the one to find the "cure" regardless of profitability issues.
Thank God for modern medicine.
