Just cause he ain't the president anymore doesn't mean I can't call him out on the fact that he was the worst president in US History, and an awful human being. He may have meant well. Hitler meant well, he simply wanted to restore Germany to prominence, with more land for the German people to expand into. Meaning well doesn't change the fact that he and his cronys made a blind mockery of their duties, failed to make America a safer place, permanently damaged America's standing in the world, and basically had free reign to do whatever the hell they wanted.
It's also worth noting that far more Americans have died in Iraq than on 9/11.