In the 90s (i.e. when Windows first got this splash screen), there was no concern with physical damage - after all, in DOS, just turning it off while at the C:\

In the 90s (i.e. when Windows first got this splash screen), there was no concern with physical damage - after all, in DOS, just turning it off while at the C:\> prompt was the normal procedure. But the filesystems normally used on PCs at the time didn't have journalling or other mechanisms to prevent metadata damage if the power was turned off in the middle of a metadata update, which made data loss that much more likely even for blocks that were already written.