It absolutely happens. My guess is that your machines just don't actually lose power very often. Any normal desk- or laptop won't. When you hit the power button

It absolutely happens. My guess is that your machines just don't actually lose power very often. Any normal desk- or laptop won't. When you hit the power button, it doesn't just cut the power; the system is told to shut down so that it can neatly terminate processes and unmount filesystems before halting. Takes a few seconds. At work I'm writing software for industrial machines. It's essentially a Linux system in kiosk mode running on semi custom hardware. We actually do have a power button that simply shuts off power (much to my dismay), and we have data loss all the time. We just make sure that whenever there's actually important data that needs to be stored (very seldom) we make it blatantly obvious to the user that now is a very bad time to push the power button, and sync before those warnings are removed. But we've had boxes that were rendered unbootable because someone decided to push the power button the moment an apt-get upgrade completed and a lot of updated files were still living in memory only.