On the technology side it seems unfathomable that almost everyone carries a phone with more computing power than used by NASA to land a space craft on the moon, but a modern jet airliner does not carry an independant GPS locating beacon to track its position. Had the MH370 aircraft been carrying a simple GPS location beacon, (costing less than $200) it's location, course and speed could have been known for the entire flight. Chase planes could have been sent to monitor the situation and drop supplies to any survivours witihin minutes of the crash. Without such a beacon, every soul aboard was doomed.
It also beggars belief that in a world where almost every electronic device can communicate via several wireless protocols, the black boxes in an airliner must be fished from the bottom of the ocean and dissasembled to extract their data.
This failure to adopt new technology that has become mainstream in the rest of society is inexcusable in my view.
The technology lessons from this are:
1. Modern, mainstream technology should not be ignored just because it is cheap.
2. The cost of not using modern technology is often much more than using it.
3. The value of data is often underestinmated until it is lost.