Walls attempts to defend the traditional doctrine of hell against annihilationism and universalism from an Arminian perspective but gives too much away without deeply engaging with the Early Fathers, the Scholastics, or the Puritans. Philosophical, but not satisfying.
But if hell is not perceived to be a serious threat, it is hard to see how salvation can have the same meaning it used to. not surprisingly, salvation is is less and less conceived as a matter of eternal life, and more and more as a matter of personal fulfillment in this life.
The Calvinist cannot resist the conclusion that God intends some to be damned by appealing to the law of double effect, for presumably God could have chosen not to damn any persons.
Those who prefer hell to heaven have convinced themselves that it is better. In their desire to justify their choice of evil, the have persuaded themselves that whatever satisfaction they experience from evil is superior to the joy which God offers.
So in the end, universalist interpretation of scripture depends heavily on the philosophical case against the traditional doctrine of hell. I have tried to show that that case is yet to be made.