The Stranger is, above all else, an absurdist novel. Absurdism says that the universe is chaotic and unpredictable; therefore, the individual has ultimate freedom. Specifically, Camus believes that most people choose death instead of freedom; therefore, his absurd hero is one who loves life, hates death, and scorns the gods.
Existentialism and absurdism both champion perfervid individualism against the forces of determinism and fate. Both philosophies negate the universality of religious systems that say there is a human soul that is lost or needs redeemed. Existentialism may be atheistic or religious; absurdism is atheistic. As a result, neither see any supernatural or mystical connection to the death or burial of human body.
So, in Chapter 1 of The Stranger, we have an absurd hero, Meursault, who hates useless labor, the culture of grieving and death, the rituals of the Sabbath, and the deterministic belief that a son must act thus and so after his mother's death. So, instead of crying and staying awake at her vigil, Meursault chooses to do as he pleases: to smoke and sleep. He does not even want to see her face before burial because death is both an absurdity and an abomination to him.
As an absurdist, Meursault would rather remember his mother alive. He does need the ritualistic self-loathing that a vigil and burial afford to purge him of some guilt over his mother's death. Meurault passively rebels against the culture that loves death because it denies freedom. It demands the bereaved (like Perez) to stay awake, walk for an hour in the heat of sub-Saharan Africa, cry, and loathe oneself all because of some ancient cultural expectation. Meursault and Camus beg the question: where's the freedom and dignity of life in such a ritual?