Ouch I seriously hate seeing people work in these 12 hour jobs, it's just way too much. I think that's a shift I'd always avoid and only go for it if it was something my life depended on. :I
Working longer hours wouldn't be a problem if there was a cap on amount of hours a person could work a week before being entitled to overtime pay. I work nightshifts for the moment, they are 10 hours long, but because my workplace has a cap on amount of hours before I'm entitled to overtime pay, I get compensated both financially and have more days off than I do when I work 7 hour day shifts.
The problem with long shifts like these is when the workers aren't compensated with enough time off to recouperate and actually have a social life.
Another bad experience I had was in my first and (sadly) only IT job. I had done really well in school, had one of the highest grade point averages in my class and was hired at large international IT company before I even left school. The starter pay was really good, and I was really excited to start working. Sadly it mostly went downhill from there. It started with being assigned a project, sit around the office for several weeks having nothing to do except going through the required company CBTs (course based training), most of which were riddiculous and pointless, awaiting the start date, only for the project to be terminated and the other workers being assigned to it returning to the main office. We then proceeded to sit there for weeks on end waiting to be reassigned, but it wasn't until after 3 months of being benched that I finally got assigned another project.
Travelling there, my spirit had been renewed, I was finally gonna do something worthwhile. I was met with a friendly enough crowd, but was a bit discouraged when the team manager started with belittleling the field I wanted to specialize in (GUI). I somewhat got why as he was tired of clients only ever caring about the GUI and not so much about the rest of the application, but at the same time it was upsetting to me to hear him talking about how the GUI could just be thrown together at the very end of the process. Then we were tasked with doing paperwork for three months, not only that, but every thing I was assigned turned out to be pointless (like giving me the task of writing documents detailing what the client wanted only not giving me any opportunity to actually get that information from the client - basically forcing me to write a lot of nonsense) and/or scrapped quickly after I had finished. It didn't take me long to feel like dead weight, and it certainly didn't help that I was working long hours in a different town, which meant I didn't have any social life to speak of. My colleagues were nice enough, but we had nothing in common except working in the same field, so I felt very much lonely for my time there.
Eventually I just requested to go back to the head office, and hoped to be reassigned to a different project, one where I might actually be of use. That didn't happen, instead I spent nearly a year being benched, being passed over for project opportunities, even ones where I would be an ideal candidate. My self worth fell down the drain, because basically I was sitting at an office 8 hours a day with nothing to do. It might seem ideal to be paid well to sit around doing nothing, but it really isn't. You feel like crap, you feel worthless, time feels like it takes forever, and you feel guilty over not doing anything for the money you're earning. After spending several months like that I started secretly looking for other jobs, hoping to salvage my career in some way, but the problem is that in the IT world your first job is alpha-omega. If you have nothing to show for from the job, you are worthless to any employer. Doesn't matter how well you did in school, no one wants you.
I ended up having to change career completely to finally get away from that soul-draining place.