The AmigaOS, since the beginning, had no problem to deal with power off-s. That's only when I arrived on the PC that I felt very strange to have to do a software shut down instead of pressing a hardware button. Nonsense.
This is not exactly true. It's true that you wouldn't break your OS install by switching power off at random times, but if you had something in the middle of writing a file to disk, then it was sure as hell going to leave that file half written.
For sure, there was no "software shut down", but the issue with that was it put the burden on the user to be careful about when they shut it down if they were saving stuff to disk. The floppy and hard drive lights (if you had one!) were there, and as long as you trained yourself to not turn it off while those lights were on, you would probably be fine, but it was far from a sure thing.
I adored the Amiga, and it was way ahead of its time in a whole lot of ways, both software and hardware, but this wasn't really one of them.