It doesn't even really matter what the common traits are of the self-selcting group of people who are here in the early days are. They exist and therefore that group is more alike each other than at a broader platform like at Reddit. Even if we are all objectively ignorant jerks, because we are similar we will feel that the people we are talking with are decent and smart because they have similar strengths and blindspots to ourselves (think of any community that is repellent to you. The people in there all seem to think one another are wonderful.)