Because everyone at the 51st percentile and below for intelligence forms a voting majority, and systematically disenfranchising people based on their intellect would invite abuse of the voter qualifications systems.
So we can't just put the smart people in charge. We have to slowly educate the stupid people out of existence, until the dumbest 51% are finally capable of determining the best people to make decisions, based primarily on their aptitude, rather than on their popularity.
When voting for county dogcatcher, for instance, people would look for "D.V.M." after the candidate's name, rather than "(D)" or "(R)". When people want to hire me, they look at my resume, not my hairline, lapel pin, or party affiliation.
Hey, here's an idea! What's the political science equivalent of FizzBuzz? Whatever it is, you can't get on the ballot unless you can do that thing, live, unaided, and in front of witnesses.
Because all the smart people are smart enough to see how much of a soul-sucking cluster-fuck politics is. That, and one could argue that if they're put on this earth to live a life of happiness, how could one ever possibly achieve this through a life in politics, knowing what they are getting themselves into?
Ehhh, that's a hand-wringing, self-serving generalization.
"We have the answers. We're just not soulless enough to want to go through (and perhaps change, in the process) the effort to supply them and make them help."
Whether you think so or not, personal incentives motivate people in their careers, salary being one of the biggest and weightiest. I'm not saying there aren't that many personal incentives to a life of politics, but at face value isn't exactly the most attractive career path.
Politics isn't just about being smart, though. It's about being 'charming' (sometimes for better, sometimes for worse), charismatic, a good communicator (notwithstanding the teams of people behind the scenes to help with this).
I get that it's not everyone's desired path (it's certainly not mine), I just think that saying "many of us are smart enough to have the answers, we just choose not to get involved in politics" is perhaps an... underestimation... of the complexity of some of society's problems.
