The Hells of Hinduism, Buddhism, Shinto and other Asian myth cycles are rich and intoxicating. But in brief, let us remember that reincarnation involves far more than generic rebirth into humans or animals. The Wheel of Life includes a number of realms -- and they range from the Hellish Nakaras to the Heavenly domain of the Devas.
Some beliefs throw in additional subdivisions of torment in the afterlife, but the general idea is that every soul may pass through numerous Hellish, human, animal and divine lives before finally finding liberation from the endless cycle of rebirth. It's this escape, not Heaven, that serves as the ultimate goal.
In some variations, you'll encounter a sort of dead-end Hell, a place where the worst of the worst may end up with no hope of escape and rebirth to a better realm. In these cases, we're back to a self-inflicted vs. literal quandary. Are they locked away forever because they're so debased, or do the depths of their debasement prevent them from ascending?
I leave such questions to more enlightened souls.