I agree in spirit with your stance, and it is a good solution to the shoulder surfing problem.
But generally I don’t think it’s plausible for a mass market device to counter every kind of threat, or every iteration of a more specific kind of threat.
In a workplace or home theft scenario, there are _presumably_ better ways of identifying a thief than at, say, a random bar.
My beef with this feature is that my Significant Locations haven’t been accurate for over a month, so my home location isn’t “trusted”.