Intelligence is a lot like money.
Those who've always had an abundance generally either think its no big deal, because they've never suffered the limitations of not having enough, or look down on those with less and consider them inferior.
Those in the middle have enough to see the benefits of having more, and want to improve themselves in order to get more.
At the bottom this analogy falters, but I think the point remains. It's easy to dismiss making the rest of the population smarter when you're already smart and not suffering the limitations imposed on those with less to work with. I find the notion that we shouldn't meddle and just leave those who draw the short genetic-straw to be cruel and self-serving. If the lowest common denominator is raised, chance are the whole society benefits, the world becomes a better, more thoughtful place, and the overall pie grows accordingly.