It is extremely silly to apply these measures to noncitizens and not to citizens. Like Ned50 said, if they can't use a stolen or borrowed green card because of the fingerprinting, they'll just use a stolen or borrowed passport where the fingerprinting doesn't apply.
Another silly aspect is the fingerprinting on departure. What is that supposed to accomplish? Unless they're going to take fingerprints after the airplane has shut its doors, it makes it easier for the bad guys to fool the government into thinking they have left. Just give the fingerprint at the boarding gate but don't go on the plane. Or go on the plane and come off before they shut the doors. And unless they plan to check passports at the boarding gate and force people who aren't US citizens to give a fingerprint before boarding the plane, they can also fool DHS into thinking they're here when they're gone. Just get on the plane without giving the print.
It's nothing but a power grab, and a way to make money for the owners of the security companies (many of whom are Bush's friends).