Okay, this might just be a drunken rant, but...
I really do think that Earth is the place where they send people who were too evil for hell. It's the ultimate punishment that far surpasses "hell." I mean, in hell, there's pure "punishment." You get tortured, mutilated, damned, etc. Fortunately, in hell, you have no point of reference. After a while, you get used to your "punishment." Eventually, the 1,000 lashings a day will just be routine. The constant sorrow and depression will just be normal. Thus, Hell is ineffective at "punishing" anyone.
However, Earth makes a much better torture ground. Honestly, if I was Satan, I would move my HQ here. In hell, you're limited to 24/7 torture, misery, heat, etc. Here, on earth, you get a nice blend of both torture and misery, combined with the complete opposites of each for short, ephemeral durations. As a result, each "tortured soul" endures his/her fair share of pain because he/she has an accurate source of reference. He has the up to compare with the down... one moment a person's life can be going wonderfully, and the next moment it can go "boom" in his face, and he quite readily recognizes the contrast.
What better torture than the constant but unreachable goal of happiness? What better torture than the constant but unreachable goal of love? What better torture than the constant but unreachable goal of friendship?
Pain you can get over. Emotional suffering's quite another thing.
I used to think that people who committed suicide were stupid, shortsighted people. But, really, perhaps we are the shortsighted people. Perhaps they knew what they were doing. How much worse could pergatory/hell/whatever be than our own, personalized hells-- bereft in a sea of loneliness, hatred, love, sorrow, lust, and greed?
This is by no means a cry for help or some other bullshit-type "you mentioned suicide and I have to save you" type of crap. I already have death on my conscience, so don't read into the lines. I'm just saying this to play devil's advocate: maybe I was wrong in misjudging people who chose alternative lives-- err, deaths. Maybe they knew a lot more than they were letting on.
Cheers.