As people around the world move further and further away from acknowledging the existence of their Creator, it is no accident that there is a move, similar in degree toward a rejection of life itself. As an atheist world-view becomes absorbed into the minds of young people, a desire to end one's life increases dramatically as soon as life's inevitable suffering, pain, loss and grief make their appearance.
This life that atheists say they hold so incredibly dear is given up pretty quickly once life becomes real.
Atheist Richard Carrier give a glimpse into the reason why.
“When we have exhausted all options, and still conclude there is no longer any prospect of happiness, death becomes an acceptable alternative.”