It is because we as human beings have an innate desire to be happy and survive (live for all eternity in eternal bliss). Hence the reason why we have beliefs such as Christianity which offer an eternal blissful life. It was an escape from suffering and death. It is a survival mechanism. I myself don't have that other mechanism which defies that survival mechanism. I am not the type of person at all who finds meaning in a finite, suffering, unhappy life. This life is not compatible with who I am. The only life that can ever be compatible with me is one where I feel good for all eternity, no suffering, and can live forever which I don't think is a life that even exists. So I might as well give up on this life already now. If I can't have any life that is compatible with me, then there was never any meaning or anything for me at all in being here.