re: What about all the Homeland Security alerts?
As the site points out, America is full of targets, and not rebuilding high towers is not going to eliminate the target list.
But it doesn't make sense to me to build these humongous buildings anymore. I mean, they look sort of like fun, but so is the world's largest Ferris wheel.
Some of humanity's most glorious achievements have no real "sense" to them. Going to the Moon or Mars might fall into that category according to some people. ;)