There is generally an inverse correlation between the effectiveness of solving a problem and the directness of the approach. If you would like to cure cancer, the most effective way is to cure cancer. The next most direct approach is to help the doctors who are curing cancer. The next most direct approach is to help the medical companies who are helping the doctors who are curing cancer. And so on.
Having "a mission" is of paramount importance to succeeding, but it bothers me when we believe we're on a mission to solve a problem that we're simply not solving. A photo sharing application could say they're improving the lives of cancer patients by allowing them to see photos of their grandchildren, and yes, by the letter that is a true statement, and honestly maybe that's all the patient really wanted -- to see photos of their grandchildren, but to me it seems like an indirect drop in the bucket toward solving the real problem.
I feel like this thinking is actually poisonous to the ecosystem. It prevents us from solving the real problems we've set out to solve by deluding us to think that by building some indirect tool for people who may help people who may help people who may actually solve the problem, we've accomplished our mission. We haven't. It's a text editor, and you have to see it for what it is. If we want to cure cancer, we need to sit down, understand the problem landscape, and solve it without five layers of indirection. Otherwise, we shouldn't be stealing the thunder of those whose actual mission is to cure cancer.