The first question was why isn't everyone trying to change the world, with the underlying assumption that everyone should be. However, it isn't obviously the case that the world would be better if everyone were trying to change it. For one thing, trying to change the world mostly means trying to change other people. If everyone were trying to do it, this would be a huge drain on everyone's attention. In addition, some people are sufficiently mean and/or stupid that their efforts to change the world make things worse.
At the same time, some efforts to change the world are good, or at least plausible. Is there any way to improve the filter so that we get more ambition from benign people without just saying everyone should try to change the world, even if they're Osama bin Laden?
The discussion of why there's too much duplicated effort in science didn't bring up the problem of funding, which is probably another version of the problem of people not doing enough independent thinking.
There was some discussion of people getting too hooked on competition, which is a way of getting a lot of people pointed at the same goal.
Link thanks to Clarity