Maybe 99 times out of 100 someone means to type "fuck" instead of "duck", but it's a completely legitimate UX decision to optimize preventing that 1% case, even if it's annoying the other 99% of the time.
Maybe, but only if there's a way to opt out of being annoyed 99% of the time. An "I'm a grown-up" button.
I think this used to be true on Android as well.