Says much about this airline and their commitment to safety. Any airline with a sincere concern about safety would want ALL the information possible to determine what exactly happened.
There has been substantial "reverse engineering" going on, but on the biggest scale to trace back to a starting point. The goal, of course, is to find the primary wreckage site. Scientists have been performing drift analysis and they are suggesting that the crash location may be slightly north of the primary search zone. Your point about possibly finding pieces throughout the drift zone is well founded. It is just that there has to be a primary wreckage site that will have the majority of the aircraft. And, it is usually assumed that the primary wreckage site will give the best chance of solving what exactly happened.
