I think defining other people to be "profound[ly] misunderstanding what life is about" just because they do not believe the same as you when it comes to something so fundamental and personal as one's life is much closer to "the apex of egoism and arrogance and all that is wrong with the human mind".
We don't need room for new people with new ideas, room isn't the issue: as far as we know so far, the Universe is virtually infinite. When we come around to defeating death (it's bound to eventually happen) we'll start terraforming, doing generation-ships to reach even further, and the rate of growth of human knowledge will reach an even more unimaginably fast pace.
We don't need room for new people with new ideas, room isn't the issue: as far as we know so far, the Universe is virtually infinite. When we come around to defeating death (it's bound to eventually happen) we'll start terraforming, doing generation-ships to reach even further, and the rate of growth of human knowledge will reach an even more unimaginably fast pace.