There is one New Testament text directly related to HT, given in Matthew and Mark:
As for that man [the betrayer], it would have been better [kalon] for him had he not been born [ei ouk eggenêthê] (Matthew 26:24, Mark 14:21).
But that text simply does not sufficiently support HT. First, it does not say that it was better for Judas not to have existed, but at most that it would have been better for him not to have been born. Since Judas had already existed by the time of his birth--I say he existed about nine months before his birth, but in any case surely he existed some time before his birth--the counterfactual taken literally compares two scenarios: Judas being born and Judas dying in utero. Now had he died prior to birth, his eternal destination would be wherever Jewish babies ended up after death--either heaven or limbo. On this reading, then, we are told that Judas would have been better off dying in utero and ending up in heaven or limbo than wherever he ended up. (If he would have ended up in heaven had he died prior to birth, then the text does not even entail that Judas went to hell. Maybe he would have been better off had he died in utero because then he would have ended up in a better state in heaven or because then he would have avoided purgatory.)
I don’t know on what he bases his interpretation. I take the phrase to be an idiomatic way of saying it’s preferable had he never existed. This phrase has an OT counterpart in Job 3:3, as well as paraphrastic equivalents in other Jewish literature. Cf. D. Clines, Job 1-20 (Word 1989), 81-82. And, by the same token, it’s an idiomatic way of expressing the worst conceivable fate. Cf. C. Keener, A Commentary on the Gospel of Matthew (Eerdmans 1999), 626. An avoidable fate had he never existed. He’d be better off not to exist in the first place given the doom that awaits him.
Second, the word kalon might also have been translated as "noble" or "honorable"--in classical Greek that is the primary meaning and the word seems to have that meaning in some New Testament uses as well. Thus, even if we take the "had he not been born" non-literally as meaning "had he not existed", the text could simply be telling us that it would have been more noble or more honorable for him had he not existed, rather than altogether better.
In context, the meaning of the word is determined, not by its isolated occurrence, but by its semantic contribution to an idiomatic phrase.
The other part of HT's Scriptural warrant are the scary descriptions--lake of fire, worm that dieth not--of what existence in hell is like. But we should read Scripture consistently with Scripture. And Scripture also tells us of a God who loves all, whose sun shines on sinner and righteous alike, who created everything and it was all good. Thus we should temper our interpretations of the harrowing descriptions with the conviction that God does not create or sustain in existence that for which it would be better not to exist.
i) Pruss needs to exegete his prooftexts.
ii) His objection is also simplistic. God doesn’t create an ensemble which is worse overall, but it doesn’t follow that the fate of each individual component might not be worse for them.
(Objection: Maybe it is agent-centeredly worse for the person in hell to exist than not to, but it is better that she exist than not. Response: But better for whom or what? God's activity is primarily guided by love.
i) Why is God’s activity primarily guided by love rather than justice?
ii) As far as that goes, is God really acting in the best interests of the damned?
When he acts for a good cause, he does so for someone or something. Is it better for God that the person suffer?
That’s misleading since the question at issue isn’t suffering, per se, but penal suffering. Isn’t justice intrinsically good?
Tertullian suggested that the saved will get joy from watching the punishment of the damned.
That’s also simplistic. It can be good to know that the wicked finally receive their comeuppance. That doesn’t require a public spectacle–although there’s sometimes a place for that as well.
One might ask, of course, if it is possible to have eternal suffering and yet to have a life worth living.
But what if eternal suffering is meant to be punitive? Retributive? Then it’s not worth living for them damned, even though it’s still worthwhile.
Moral improvement (though one never actually reaches moral purity)
Why should hell be a place of moral improvement? What’s the point?
With so many alternate readings, the probability of the reading that Judas is going to go hell and in hell will suffer such torment as to make it that it would have been better for him not to have existed seems low.
Pruss is one of those men whose strength is also his weakness. He has an agile mind. But this betrays him into misplaced ingenuity. Intellectual ingenuity should be deployed to defend truth, not evade unwelcome truth.