Why the instinct to survive?

[Whateverist]

Note how that while most of us realize that it's all pointless, we go on living our lives anyway.

But why... and why do human beings seem to be the only living organism that contemplates suicide?

What sort of why-answer are you looking for? Life and experience is everything. There isn't anything to trade it in for.

Frankly you continually ask the sorts of questions xtian apologists often do, questions which it only makes sense to ask if you think there is really a supernatural punchline to the big questions.