Personally, I'm afraid of suffering and afraid of dying. I'm also afraid of witnessing the suffering and death of those who are close to me. And no doubt I project these fears on those around me and those to come, which makes it impossible for me to understand why everyone isn't an antinatalist, just as I have to assume pronatalists can't understand why everyone isn't like them.
Tragically, some people believe they are going to heaven when they die just because a few drops of water were sprinkled over their heads a few weeks after their birth. They have no personal faith, have never made a personal decision, and are banking on a hollow ceremony to save them. How absurd.