I don't think people 'chasing legacies' are generally concerned with whether 'most people' are remembered, that's exactly the point isn't it? Standing out?

A better 'problem' to point out might be the timespan over which few legacies that are remembered originate. 'I want to be the Tutankhamen of my time' is all very well, but there's no reason to think there will even be one.