I recently came across this post: Ten Photos Proving the Taiwanese Can Sleep Anywhere, Anytime
I'm not surprised.
I'll even say that there's more than a grain of truth to this: I too have noted a higher percentage of people sleeping in all sorts of places at all sorts of times in Taiwan.
It starts in childhood, when as kids they go to school all day, then to cram school, and they're lucky if they get home at 11pm. I used to get on the MRT at Taipei Main at about 10pm twice a week - the person driving me would race to get there before the cram schools let out at 9:45 and the MRT was crammed to the gills with students. Then they've got homework. No free time, of course, not during the week. My estimate is that the average Taiwanese student gets about 3 hours of sleep a night.
OK, seriously, maybe not 3, but not more than 6.
There are exceptions to this rule - I tutor two girls on the weekend (it's not really a "class" - it's English Fun Time and I do it more because I've become attached to the girls and invested in their future than for the money) and they don't attend cram school every night, although they are pushed to do well academically within the bounds of reason.
Then there are the casualties: the nephew of one of my former clients (she's left that company), who had to be out the door at 7am for school, then cram school, home at 11:30pm because he lived out in Taipei County (I believe his parents own a small apartment in Taipei City, allowing him to attend high school here, but don't actually live there - it's actually quite common among the well-off in Taipei). Then homework, which he barely kept up with, if at all, then finally bed. He did all the extra homework on the weekend, as well as taking additional classes. By the time my student told me her concerns about him, what she described in his personality fit the signs of depression quite accurately - although I'm not a psychiatrist, I'll at least say that he should have been screened. It's sad that knowledge and treatment of mental health in Taiwan is so lacking that that'll probably never happen. I can't say, of course, if that was caused by his *ahem* rigorous academic schedule, but I sure can take an educated guess.
Then you get four years of relative freedom in college before you're bounced into the working world (or for men, military service, which might actually be another few years of decent sleep) and are working until long after a healthy person should go home to enjoy their family - usually around 7 or 8, but also fairly often until 9 or 10, and not uncommonly are the newest employees stuck with work on the weekend - unofficial work, of course, so they don't get overtime or comp time for it. They're just given more regular work than they can possibly do in 8 or even 10 hours.
It doesn't get much better as you climb the ladder - my students regularly report getting home at 9pm, 10pm or later - and I tend to teach the higher-ups.
When I ask, the most common answer I hear for how much sleep people actually get in Taiwan is about 6 hours, often less. I don't know about you, but while I can live on 6 hours, after a week or so of that I'm drained. It's all I can do to stay awake no matter where I am. I start to doze off whenever I sit down. I tested the limits of this in the USA, when my natural bedtime (around midnight) clashed with when I needed to be up for work (around 6am, maybe 6:10). I couldn't afford the thing that would have allowed me to wake up later - that being a car - and couldn't force myself to sleep before 11:30pm, maybe 11. I sure could doze off on my lunch hour or on the bus, though!
So is it really any wonder that you see people sleeping in all sorts of contortions in Taiwan?
Maybe if they didn't feel the push to study and work themselves* to exhaustion it wouldn't happen.
*by "themselves" I don't mean everyone, it's one of those general statements that's meant to describe observations of trends, not individuals