Most people under the age of 25 don’t have their brain wired right yet, particularly the ‘no that’s a bad idea’ part. And they think they’re immortal. There are exceptions, and it never properly develops in a lot of adults, but really smart kids who make staggeringly bad decisions is a common thing. Age varies, but 25ish is my experience.
Also, many people go to college not because they’re particularly smart or have a need for it, but because that’s just what you do. They’re not necessarily smarter than the high school dropouts, or the ones who graduated high school but didn’t go to college - they just had better resources.
Then frats actively concentrate the worst people. Add peer pressure, and you’ve got a regular F5 hurricane of testosterone, alcohol, weed, and bro. None of that leads to good life choices.
10 years from now a lot of them will be perfectly normal socialized adults… but then a lot of them will be in sales.