Now, I'm sure the experience varies from region to region, but where I went to school frats and sororities were downright shameful organizations. One pledge died from alcohol consumption, another lost its charter for refusing to do any community service and sending people to the hospital almost regularly for alcohol and alcohol related injuries, yet another had their house condemned and taken away after refusing to fix dangerous defects in the flooring among other things (someone fell through the floor and into the basement). I know almost no frat brother that had any ambition other than to drink themselves to death before they turned 30. I remember a couple of them volunteered their sexual habits to me: like proclaiming their abstinence from condom use and propensity to "hit it raw" and "pull out and shoot it gangsta." They were surprised that I used condoms... pretty much nobody they knew ever did. The only one that I know of that did happen to "make something of himself" got accepted to Penn's dentistry program, and he constantly told me how great it was going to be because he would barely work, make scads of money, and could get away with a lot more negligence and illegality in dentistry than in medicine. He gave me a few examples of illegal things that went on undetected in his father's dentistry practice but I can't remember them any more.
I could go on, and these are just the frats. The sororities just seemed to me to be social clubs that relished being able to exclude people. I dated, or I guess I should say I was just "involved" with, a sorority sister so I know how little these organizations do anything meaningful and how often they just drink and screw. I met this girl freshman year, before she joined a sorority, and she was much more normal. Once she joined she literally became an alcoholic that could barely pass a general education requirement. I'm not sure if she was always insane and just hid it better, but the sorority brought it out of her in full bloom.
I'll say it again: I know that this probably isn't the same at every school. But I have a hard time believing it's a lot better anywhere else. I never joined a frat, I just befriended people from my classes that I liked talking to and hanging out with.
The stereotype is spot on where I went to school.