If instead we valued Death as an intrinsic good, we would be making the hard trade-offs in the opposite direction.

Not necessarily. We could value both life and death; we might then want to live some amount of years (or live long enough such that we accomplish some amount of "living", i.e. derive the desired amount of benefit out of life), and then die. Dying before getting all the life we want out of life would leave our desire for life unsatisfied, while continuing to live longer than that would stop us from satisfying our desire for death.

A (possibly equivalent) formulation might be to say that we derive diminishing marginal utility from life, such that as some point it is outweighed by the utility we derive from death.