I don't want to die because there are people who care about and depend on me here. If I were dead they would be sad--I wouldn't want that for them. Not to mention the fact that I actually enjoy life. Why would I want that to end? Because of some half-baked fantasy about an all-you-can eat buffet in the sky? Please
I care about the future of humanity because I think we will eventually get IT right. I have faith that one day humanity will reach a point where suffering no longer exists. Life is a beautiful thing. Why would anyone want to see humanity's potential snuffed out regardless of whether or not they believe in abstractions like a deity or an afterlife?