Not sure why this thread is just about "drop safety"? You can test this by hitting the rear of the slide with a small hammer. And it fails.
My 1911 is on my right hip at 3-4 oclock. Guess what else is near there? Door frames, countertops, circus clowns, kids with pointy foreheads, horse hoofs, stair rails, power transformers, tool boxes, truck tail gates, etc. (all things I've slammed my pistol into over the years)
All kinds of things that will hit that pistol with much more force when a 260 pound, 6'3" man walks into them at full speed.
There is no excuse for Sigs drop test failures. 1911's weren't too safe for many years, but that's been pretty much mitigated with lightweight firing pins or 80 series safeties. And the olde 1911 lack of safety isn't an excuse for the modern pistols failures.