There's an interesting piece in Metropolis about the phenomenon of missing the last train in Tokyo. Anyone who's been to Tokyo and stayed out late has had to tangle with the last train, or likely even missed it. Trains stop running frustratingly early, and, as the author of the Metropolis piece points out, taxis are expensive. He then goes on to offer that missing the last train might be some kind of face-saving exercise, an excuse to let loose.
Lots of places have last trains, including Seoul, one of the places he mentions as being not like Tokyo, convenient bay comparison. And apparently Seoul is also not big, like Tokyo. Um, Seoul is massive. But if you're visiting, perhaps you're staying at a centrally located hotel. This goes for New York as well. No trains? Just split a cab with your coworkers. It's a bad argument because the situations are different. Yes, Seoul cabs are cheap, but NY cabs are just as expensive as Tokyo's, and if you live in the buroughs it sucks just as much as living outside the Yamanote loop.
OK, so the fact that the trains stop running around midnight is annoying. I've missed a few in my time. I like to walk so didn't mind hoofing it, even when it took 3 hours to get home. Usually I would just plan to miss the train and stay out all night. But the way the article paints it, missing the train is a license to party hard. As if Japanese people need this excuse to drink a lot.
The trains stop at midnight. So why are people smashed and falling down at 7pm? You think these people need an excuse? If anything, the fact that people know the trains will stop may encourage them to drink more, faster, so they will in fact not miss it.
If you do miss it, what do you do? If you've been smashed since 7pm you probably can't see so you pass out in front of the station gates and wake up when they open at 6am. Or you crash at a capsule hotel (it's why they're there) or a manga cafe, which the author oddly sites as a reason people might purposely miss the last train. Has he ever even been to a manga cafe? They're not that great, and sleeping in a chair in a cubicle is no good time.
No, people stay out all night because it's fun. All over the world people do this. Whether there's train service or not.