I'd extend Eugene's reply and point out that both the original and modified version of the sentence are observations. As such, it doesn't matter that the two sentences are grammatically similar; it's entirely possible that one is observed and the other is not. History has plenty of examples of people who are willing to do harm for a good cause and end up just doing harm; history does not have plenty of examples of people who are willing to cut people open to remove cancer and end up just cutting people open.

Also, the phrasing "to end malaria" isn't analogous to "to remove cancer" because while the surgery only has a certain probability of working, the uncertainty in that probability is limited. We know the risks of surgery, we know how well surgery works to treat cancer, and so we can weigh those probabilities. When ending malaria (in this example), the claim that the experiment has so-and-so chance of ending malaria involves a lot more human judgment than the claim that surgery has so-and-so chance of removing cancer.