It is unhelpful to most people on two levels - firstly, about half of us are below median intelligence. Secondly, not everyone can change the world all at once. There are too many people and too few things to change for that to be feasible. By the numbers, most people are going to have to be satisfied with having no real impact.
I think you are severely underestimating the local effect an individual can have by influencing life, albeit on a smaller scale. Not everything has to be on a world-scale. In my case, I love watching movies and discussing them, but never applied that in any way to my environment – until I started a small, local film club, which has given me a real sense of having a bit of influence.
