You're taking a very modern, liberalistic view on the idea of "punishment". For a lot of people - hell, for the vast majority of people - punishments are about delivering justice. As such, eternal hell is there to torture those who deserve to be tortured.
I don't personally agree, but I don't see how you didn't see this.
“These are my principles; if you don’t like them, I have others.” – Groucho Marx







