The shattering of the ego - the understanding that i am truly unimportant, nothing special, no different than anyone or anything else, seeing through the illusion that there is no distinct i and realizing i am the universe - should automatically result in lack of all desires, including the desire to live because fear of death is ego.
Why doesn't it then?
The simple answer is that i have not yet reached the point i'm describing above. But if self preservation is directly proportionate with the size of the ego, why should i even want to?
On a more abstract level, the ego is as natural as anything else, so all the points of view about it are equally valid, be that egofullness or egolessness and anything in between. What is then the buddhist middle way good for i wonder? Is it simply follow the "everything in moderation" rule of thumb? But to what end? To live a mediocre life for as long as possible? Both egofull and egoless men die and nothing really matters in the end but isn't one more fun than the other? Fun being pleasure*, isn't hedonism the only thing i'm really doing in this life?
* by pleasure i mean any kind of self-satisfaction (and not just immediate), no matter how altruistic or noble the actions they still ultimately give me pleasure thus feeding my ego (even suffering can fit in this category like if by it you can save someone's life or if you sacrifice yourself for gains in the future)
