The issue is where do you go? What if you leave and your evacuation spot gets a direct hit? Also, it isn't like every one can just drop everything and leave, especially when they don't have anywhere to go. If all your family and friends are in the same area as you, where do you go? Not like people have an unlimited amount of money and get a hotel indefinitely.
It isn't as simple as GTFO.
I do understand the sentiment, and agree but it isn't as simple as it sounds. Especially if you have a family. Best you can do is get out of areas that always flood or are dangerous in storms and hope for the best. But even then, storms are just so unpredictable. I have been through several hurricanes and tropical storms. Especially when they hit at night, you just sit in the dark and hope a tornado doesn't come through or flood waters. It's terrible, but part of living on the coast.