Since Sully's actions are being held to be the gold standard of dealing with an unexpected event, it might be worth comsidering his options again.
Returning to the airport he had just taken off from was unviable.
Landing at another airport nearby was potentially possible but involved flying over a built up area.
Looking for the longest, largest unobstructed area to put down the aircraft.
Aircraft are strongly built to survive in the air but perform very badly when coming into contact with solid immovable objects like buildings. Aircraft are designed to potentially survive a ditching, they even carry liferafts and life jackets for passengers and crew.
Sully acted in the only logical manner to ensure the best chance of survival for those on board. Even if the aircraft had hit a vessel on the Hudson and disintegrated, it is likely that some on board would still have survived.
If he had gone for a landing elsewhere on land and hit a building, undoubtably everyone aboard would have perished.
It wasn't such a hard decision to make although the flying skills and great deal of luck required to carry out a successful ditching were exceptional.
An automated control system may well have opted for heading for the nearest airport if the figures indicated it was possible to glide there. The automated system might then be caught out by windshear nearing final approach and landing, because that was a factor it was unable to detect in advance. So the aircraft could have landed short and hit buildings killing everone aboard and causing casualties on the ground. A human pilot will at least consider the possibility and additional risks of windshear and act accordingly.
Automation can only act in accordance with the information it receives from its sensors. It cannot autonomously consider the possibility of events for which there are no data, so it is pointless and impossible to plan ahead for every eventuality.
Computers effectively live in the moment but humans are always looking to the future, even if it is a simple as putting one foot in front of the other, we are constantly aware of our surroundings and potential danger through millions of years of evolution.
Perhaps computers will evolve sentience and be able to consider and take control of unlikely events, but will a sentient computer put people or its own survival first? The survival instinct is the most basic one found in nature. All living things ultimately act in a way that best ensures their own survival, so why would a sentient computer be any different? Could a rogue sentient computer decide to crash an aircraft deliberately because of some perceived threat to computers generally? Perhaps one of the passengers on board is a computer programmer intending to 'adjust' the level of autonomy of the computers used in aircraft or false data is being input for testing purposes, shades of HAL in 2001.
Automation should assist to the point where it disappears into the background, not assume overall control. That is a human perogative.