Absolutely. If anyone is annoyed because they evacuated for nothing, they just don't seem to get it. When a storm of this magnitude is headed your way, you've got to evacuate before it's certain whether or not it's going to hit you. If you wait until it's certain, it's too late to evacuate. So you leave, even if it ends up not hitting you. And instead of thinking you evacuated for nothing, you're thankful that your city didn't get hit after all.
Better safe than sorry... and always better to err on the side of caution. I don't see the Houston/Galveston evac as either unnecessary or a failure. It was necessary, it worked, and it served as a test-run and as practice for future events.
The way I describe it to people is: Here I've got a box of twenty rounds of ammo. Nineteen out of twenty are dummy, one is real. I'm going to take one round at random, insert it into my gun, point it at the chair you're sitting in, and pull the trigger. Are you going to get your butt out of that chair or not?