Warning: worthless evidence-free armchair evopsych speculation coming up:

The benefits of technology and techniques don't spread right across the whole population immediately - the primary benefit goes to the inventor and those near to them.

So, in the ancestral environment, if inventing a new kind of pointy rock to better kill dinosaurs gives you +1 fitness points, and lying around watching stone-age TV until your neighbour makes a pointy rock then stealing it gives you +2, then genes for inventing will spread until everyone has a 1/2 chance of having an inventor for a neighbour, at which point equilibrium is reached and both gene types will do equally well.