I wouldn't say it is necessarily about finding a cure directly, but about gleaning information about protein interactions that can be applicable in a wide variety of areas. Science builds on itself and a lot of advancements in one area can lead to breakthroughs in other areas that no one could have conceived of. That is why Boinc research has such a large utility, and precisely why incentivizing such research is very important (Gridcoin):

The University of Texas Medical Branch in 2007 launched a dengue fever drug research program (Discovering Dengue Drugs – Together) that took several years and a few hundred thousand volunteer computers at the World Community Grid to screen three million compounds, several potential candidates that would kill the dengue virus were discovered.