The coming of Jesus wasn't just in Bethlehem. That was just the beginning. Indeed He did. We don't talk more about it because we know the lessons of church history. That's reason number one.
Nobody knows the day.
He only suspects and believes that. And we don't talk about it because it becomes too easily a clever maneuver to divert our minds and attention from the job that needs to be done today-saving the tragic, pitiful lives of people who are empty because they do not know God. In my travels I come in contact with church leaders around the world. Today, Christians in the Third World are not at all happy about the evangelical believers of the United States of America, who are obsessed with the idea that Jesus is coming back soon. They feel it's very dangerous to think that way.