Besides, in the small event of deployment-caused downtime and problems, who is to say you have enough time to restore service by the time your customers come online? By taking advantage of the clock you've only given yourself a few more hours to deal with any problems, rather than finding ways to not have any problems in the first place (canary-in-the-coalmine-style deployments, etc).
Right, and that's where I strongly disagree with the author. Sometimes finding and taking care of that last 0.1% risk of failure just isn't worth it. Sometimes you're better off babysitting the deployment for 30 minutes once or twice a month rather than spending valuable development hours updating your deployment scripts to be fully automatic and handle every possible contingency.
If your deployment scripts are fully automatic, you can enjoy the (many) benefits of deploying more often than once or twice a month.
Shouldn't I decide where I want to spend my energy?