Because he's smarter than you and his opinion is better than yours and he must broadcast his opinion of what other people are doing that has zero negative impact on his life because, well, he's smarter than you and his opinion is better than yours. That and nobody gets the well-deserved ostracization for being a douche in public or the well-deserved pop in the schnozz anymore with the anonymity of being a Keyboard Warrior. But I'm sure your question was just hypothetical.