bburks,
I think the question you should be investigating is not why pilots cannot recover from upset situations, but why they get themselves in an upset situation in the first place.
There are a number of threads running on PPRuNe at present which are dancing around this issue given that airlines have found a new favourite way of committing industrial homicide. Gone is the favourite controlled flight into terrain to be replaced with loss of situational or attitudinal awareness.
hoggsnortrupert has, in my opinion, pointed to the root cause of the problem and you have alluded to it in your question, training.
I live and fly in Australia which still has a strong GA environment which is the traditional way of giving pilots experience before they are let loose in the big stuff. In the past a pilot could expect to spend several years in GA before moving on. This gave them extensive hands on flying experience including flight in instrument conditions. They took these skill into the airline environment where their captains had also come up through the ranks with the same background. The result was a cockpit experience level that could cope with automation failures, upset conditions, wind shears and the like.
The current trend is for "fast-tracked" cadets who do not possess that real world experience. Now it is not possible to take a European cadet and give them the GA experience that an Australian pilot will get but it is possible to extend their training to include much more time in a simulator dealing with these types of problems and how to recognise it and deal with it without the need for an autopilot.
It is not happening today and the results are in the crash reports with increasing frequency.