Let me respectfully disagree.
While there's some bad place in most religions, there are different conditions for going there. For example, Hel was reserved for these who didnt die in combat, afaik. No matter what, you go to Hel if you didnt die in combat, and you go to Valhalla if you were a brave warrior and died with a weapon in your hand. Greek Tartarus was for these who sinned heavily (not just your everyday greed and lust). For example, you were a pretender god who denied the previous Pantocrator. Etc etc.
And only Christians/Muslim 'send' to their Hell these who didnt convert to their God. AFAIK, if they are to be believed, even the most rightous nonbelievers will be tortured for all the eternity just because they didnt accept the one and true Faith and didnt pray to the one and true God 4-5 times per day on their knees.
Thats some punishment if you ask me.
It probably has something to do with these religions success - maybe as much as the swords of their adepts. Fear is a powerful factor.
(What a joke must be to choose one of these religions only to find out that you guessed wrong and thus go to hell.)