So pick something that requires very little capital, like saving the 16000 children who die every day from starvation-related problems in developing countries.

"I lack capital" is a very silly excuse given that the HN community are among the richest people in the world... by definition, if you have the luxury of even thinking about moving to Mountain View and starting some web site, you are among the richest people in the world. A lot of people wake up in the morning and their first task is to figure out how they are going to eat today.

There is a great scene in Curb Your Enthusiasm where someone spills wine at the table and the lady yells "Somebody Do Something!" and Larry says "Why the f*$k don'you do something," I never understood these clever articles explaining why smart people are selfish. Most people writing these articles are more than capable and often (in Kara's case) rich with access to attention of the masses.

There are plenty of people with big ideas, feature them, befriend them, help them get money. If you think something is important build it or help they people building it leverage it. The solution is never to make the people doing things you don't consider big feel small themselves.

While I agree with much of what you are saying, I disagree strongly with the last sentence. I think if one feels that a certain career path is petty and selfish, one must make that clear. The reason is that, aggregate over large populations and years of time, societal notions of dignity and respect toward certain professions, and disrespect toward others, have a substantial influence on whether people enter those professions and what kinds of choices they make once engaged in them.

Of course this is a mechanism that goes horribly wrong in some societies, but it's our job to make ours as good as we are able.

You really have to wonder though: Why dont our doctors have access to a "social doctor network" as robust and salable as Facebook? Why cant our doctors share medical records as easily and with as user friendly of an interface as instagram? etc. It might be hard to say "HEY, all doctors, you must USE THIS SPECIFIC SYSTEM" but if we could just agree on that, why cant we put the Facebook engineers to work on revolutionizing the way doctors share information?