Interesting idea (biometrics), but I agree that the technology is a long way from being even close to ready. There are also the compounding issues that would need to be resolved: letting someone else shoot your firearm, transfer of biometric data when selling a firearm, the fact that no technology is foolproof and WILL fail (system lock out on one extreme, totally 'open' on the other), and when the technology fails, is the firearm owner liable? Also, the concept of privacy rights and monitoring -- what a mess!
You're exactly right. Think about how many issues there are with even this "simple" idea, then think about the more exotic and complex ones the author suggested in his article. There simply isn't a way to do this that would have the "pull trigger, gun goes bang" kind of reliability you need in a weapon.
Imagine your gun telling you "Recalculating..." when you're trying to shoot a bad guy.
So a bad guy with a gun in one hand and a child in another can kick in my front door and I can't do anything about it? No thanks.
Or even worse...imagine a hostage situation with your own child or grandchild. You wouldn't even have the option of taking out the bad guy.