It's not that life wants to continue existing, it's that life is what continues existing. That's not a moral standard, but a matter of causality, that life that lacks in "want" to continue existing mostly stops existing.
But what I really want to say is that wanting to live is a prerequisite to the evolutionary proces where not wanting to live is a self filtering causality. When we have this discussion the word wanting should be correctly defined or else we risk sitting on our own islands.