Surely this won't make those considered stupid any smarter. Why shouldn't someone less intelligent be allowed to read and interact with an intellectual conversation. It's not that easy to group people in such ways.
it's about content promotion. Why should content-promotion algorithms be intelligence agnostic?
Because a "stupid" person might find the same thing interesting as a "dumb" person, hence the upvoting model. People who are inclined to agree are just as inclined to upvote these items, promoting them to a position where other people can consume said content.
And a dumb person may not find the same thing interesting. Do you have any research to indicate one way or the other? If not, why take a position against the notion of intelligence- and personality-based content?
Incidentally, in a sense, that's the old OKCupid model, but instead of LOLcats, it showed you potential relationship partners.