Quote Originally Posted by NigelWalmsley View Post
Well, it's not like the Good afterlife is all that much better. Most Good people will spend their eternity as a celestial blade of grass or a heavenly doorknob or something.
I don't get where this idea that people who go to the upper planes are transformed into objects comes from. What source actually says this? Good-aligned mortals die and become petitioners on good-aligned planes, the same thing that happens on the neutral and evil planes. Some of the good-aligned petitioners get converted into Celestial beings like Lantern archons, but mostly they just wander around as petitioners in environments that broadly match their understanding of what Heaven would be - like what happened to Roy when he died in OOTS. The big difference for the Lower Planes is that the fiendish powers-that-be convert essentially all arriving petitioners into-bottom rung fiends.

But more than that, even the low end of the fiendish hierarchy isn't necessarily a punishment. If you are a masochistic worshiper of the God of Pain, you presumably consider the eternity you spend in a pit full of flaming spikes to be the Good Ending.
No. If you're a masochistic worshipper of the god of pain in life you are probably sufficiently delusional as to rationalize to yourself spending eternity in a put full of flaming spikes would be awesome, but that isn't actually true, and the suffering is exactly as bad as a neutral observer thinks it would be. Someone who's brain chemistry is actually sufficiently messed up to enjoy spending time immolating while being impaled is sufficiently mentally disturbed as to preclude any alignment other than chaotic neutral.

What makes D&D really weird (to the point that even the authors sometimes lose the plot) is that it postulates that there are people who are in favor of things that are, in the real world, considered universally bad. In real life, no one is pro-terror. Even terrorists are doing what they do because they have some political or ideological goal they think it accomplishes. But in D&D, there is an actual God of Terror, whose goal (and that of his followers) is for there to be more terror in the world. Not because he thinks it's necessary to effect change, or even because it hurts some group he hates, but because he actually wants terror as a terminal value. The fact that his followers end up in an afterlife that is full of terror is no more a punishment than the fact that the followers of the God of Cooking end up in an afterlife that is full of food.
The real issue I find D&D has is that it presumes people like this are common. There are, among humans, a small number of 'people who just want to see the world burn' but they're extremely rare and tend to flame out spectacularly. Somewhere along the lines D&D committed to the idea that, if the Blood War came to an end the forces of evil would drastically outnumber the forces of good and overrun the multiverse and that just doesn't make any sense, mathematically.

But yes, in the divine sphere the various designers of D&D failed to properly differentiate between gods who are evil - because they are unrelenting violent or can't control negative impulses or whatever - and gods of evil which are manifestations of negative impulse given form. Various mythologies include lots of gods who are evil, but very few gods of evil. The exception, of course, is monotheistic traditions which tend to include a single benevolent creator and a single perfectly malevolent oppositional figure. But the number of people who willfully chose to serve such adversaries - as opposed to being blackmailed, tricked, enslaved, or intimidated into such service - is quite small.