I can understand the point, but I don´t see that happening in some decades. Airplanes have a problem that automatic cars or trains don't have, you can not failsafe them with a "STOP EVERYTHING NOW & HERE" system. In a case of fire or any other big emergency or computer failure, you simply perform an emergency stop to a side and you are out of your self driving car in 10 sec (the worst could be that your bricked car is now creating a traffic jam), unfortunately that's not the case with an A320.
It´s true that we don´t manually fly the airplane most of the time, and that 80 or 90% of flights are mostly routine that could be automatized somehow. But there are certain days, certain flights, certain airports (and this can be the same Airport that yesterday was perfectly standard) were you need to make decisions that a computer can not make. When you start encountering big thunderstorms in the radar, and not a possible way out, short final wind-shear or other limit edge operation, strange behavior or malfunction of the on board computers, systems or instruments, corrupted or missing navigation or performance data (or flying to Russia were you can not trust , in other words, unexpected situations were there are not clear rules to apply, just your experience an understanding of the basics, and a bit of that Capt. Kirk essence somebody named in other comment.
You need a really powerful and independent AI to face the fuzzy decisions that need to be made in a weekly basis. This AI needs to have independent control over the flight computers and controls, independent artificial vision, independent navigation skills not related to the normal rute computer, and a way to know when to skip safety rules completely.
If you try to substitute it with a simple AI, you end with problems like the one that didn't make the general media but could have ended with a Lufthansa crashing on the Pyrenees this last November, if it hadn't been pilot intervention ( http://www.pprune.org/rumours-news/558483-iced-aoa-sensors-s... ). The failure was of a system that exists purely to prevent pilot error. This system almost sent the A320 in to the ground. Just because the pilots were at the cabin and disconnected the air data computers a tragedy was averted.
Unfortunately this happens often enough, but doesn't make the news. The A320 model is 30 years old, it had at the beginning a number of fatal accidents due to the same computers that were intended to improve safety (like http://en.wikipedia.org/wiki/Air_France_Flight_296 or http://en.wikipedia.org/wiki/Air_Inter_Flight_148 ), but we are still dealing with automatic errors like the one of the Lufthansa ( the angle of attack fins get locked and the computers think that you are in a stall, the auto correct the stall with a dive that you can not correct manually, you need to disconnect 2 of the 3 air data computers to disable this saving behavior). Of course there is also a whole lot of money to be lost in sales if a model is declared dangerous, so complex accidents tend to be attributed mainly to the pilots, after all they can no longer give their opinion after the crash.
If something, the tendency has gone too far in to automatizing the flight. Flying manually tends to be less and less part of the requirements of big carriers, getting to a dangerous point: in some countries in Asia piloting skills are almost non existent (Korea, Vietnam, China). In China for example (at least in a couple of Airlines where a number of friends are flying) flight officers are not even allowed to land or take off the airplane, that means that if the captain has a heart attack there is a hight probability of the plane crashing. Once this flight officers are promoted to captain, they'll have almost no manual skills for flying the airplane.
This doesn't mean that safety systems are not useful or necessary, they really are, and they must be improved and to help the safety of the operation, but they can not be an end in themselves.
Returning to making a plane pilot free, you may remove humans from the inside of the plane, but they are going to be designed, build, programed, operated and maintained by humans in a human environment. I don´t see how you are going to get rid of the human error factor any time soon even if you had the perfect AI right now. Remotely controlling or even assisting pilots is a big no no, way too easy to perform a huge attack of docens of planes at a time, using just a laptop and some human engineering.