It isn't realistic for millions of people (about 2 million under mandatory evacuation as of me me typing this) to evacuate from this area. Our transportation network doesn't allow it, and for various reasons many people can't realistically do it even if it did. The obvious challenges facing elderly residents of God's Waiting Room should make that more clear, but it's true generally.
It takes a massive public effort for something like that, and that doesn't happen in part because it doesn't even occur to people that it should.
I'm not a logistics expert, but I suspect a realistic effort would involve mobilizing every bus in the region and having shelters for people to go to on the other end. It requires something a bit more than "try to get out in your car on a congested highway with limited gas options and find a hotel!"
I understand (I am not an expert!) Florida has some shelter facilities, but nothing that can meet the scale, nor necessarily ones that are adequate for the storm.
