In my opinion, the insidious nature of partial IRS failures in B737 aircraft can catch even the best trained pilots off-guard. Of course, that doesn't detract anything from the observations regarding lacking failure management and upset recovery during this accident (let alone the maintenance can-of-worms).
I suspect you may be right that in the third world there are a great many other Adam Airs who are neglecting just as much basic maintenance and yet getting away with it (for now). Unfortunately the consequences for the directors of these companies in sanctioning this kind of active wilful negligence are never serious enough. If they were likely to go to jail for 10 years or more (actually in jail that is) for signing off policies that led to such a tragic and fatal outcome then most of them would never think the risk was worth taking.
Coming back to the pilots surely the truth of the matter is that there are many journeymen poorly trained and only moderately competent pilots (especially in the third world) who may lack the intelligence and the training to be able to cope with these highly unusual and unexpected situations out of left field that only the most able pilots will immediately spot and take action to correct. Yet fortunately for most of the mediocre pilots the situation that will really trip them up will never occur on their aircraft in their pilot lifetime and so they may pass through a whole career without their mediocre airmanship skills causing any tragic outcome.
In the case of Adam Air its very doubtful these guys were exceptionally bad pilots (in Indonesian terms) but because of the risks AdamAir was taking with both their and their passengers lives only very good pilots could probably have survived the terrible risks the airline was regularly casting in to their path.
On the scale of pilot errors the error made here was clearly disappointing but nowhere near the same level of basic lack of competence and good sense displayed by the Helios 737 pilots who had minutes to realise their mistake and yet still continued to their doom.
The bottom line is that there are some kinds of insidious equipment failures on each aircraft type that will always present a risk of misdiagnosis by the pilot and a consequent tragic outcome. With this being so the only solution is surely to maintain the aircraft better so that fewer journeymen pilots make such mistakes in the first place. Of course training the pilots yet better too would help but there is only so much good that can do if aircraft maintenance is being criminally neglected.
In the much longer run aircraft can clearly be designed better to prevent most pilot induced crashes so that eventually the main causes of aircraft failure should be only sudden mechanical failure, extreme weather conditions or terrorist action. However that day when pilots are possibly no longer needed is probably still a good 20 to 40 years away.........