I for one am not going to second-guess the decision when the storm isn't even over yet. There's time to point fingers later, but now is the time to help or at least show a bit of humanitarian charity. Harvey went from a tropical storm to category 4 hurricane in 36 hours. Telling over 6 million people to evacuate within what, a 24-hour period would have jammed the roads and likely caused more deaths. Why don't you offer some words of condolence or care to the people of Houston? This is a 800-year weather event, not a judgment from God, you two-bit prophet.
From the news coverage I've watched, the rescued have said they sat out other storms, but that Harvey was the worst they'd ever seen. And there were hundreds and hundreds of private citizens out on boats, helping friend and stranger alike. They, unlike you, Mr. two-bit prophet, have a heart. They're showing charity for those in need, they're putting their heart into solid action with their hands. Unlike you.