UL situation seems extreme because they agree on most things and only seem to have a few disagreements, though how such things are handled matters. I don't think most people are actually going out of their way to meet friends who are vastly different from them the majority of the time. People who have such friends it's usually someone they knew from elementary school or high school or college at the most anyway (I do think that is the main way people end up with friends that are nothing like them) They usually aren't going out of their way to just to expand their understanding of life or something in adulthood by befriending people of all positions from every possible walk of life or something. People do like people similar to them.