I would not say self preservation is superior at all. Pleasure is a term that includes life already-- a dead thing can't have pleasure. So to maximize pleasure already means to maximize pleasurable aliveness. Life without pleasure or hope of future pleasure has no good in it-- it can't stand alone as a valuable thing. I think the thing that confuses people is that life can be present without pleasure -- separable--but pleasure is literally a meaningless word without life-- inseparable. To try a…
Even in Epicurus' example of the great pleasure one feels upon escaping a situation threatening one's life IMO includes the assumption that this life one wants is pleasurable. Otherwise we wouldn't want it. People are not relieved, for instance, if their planned medical euthanasia for fatal/intractably painful condition is postponed!