You may be correct about a dedicated shelter, but for the ordinary front/exterior doors, I believe I have seen outward opening doors on homes in Florida and IIRC the reason given was for hurricanes.

In terms of hurricanes, I have heard that one of the primary weak points is the garage because most garage doors are not that sturdy. Once that door fails in hurricane force winds and there is an opening, it's much easier for the wind to start tearing apart the garage from the inside. I assume the same danger would apply to a home, so an outward opening door would normally be more resistant to that scenario than an inward opening door that might only have one point of contact (just that little latch on many doors) keeping it closed against strong winds from the outside. Obviously, windows are also a weak point, but that's why they get boarded up.