I probably misread something earlier... Basically that they would be trying to fly over the storm and that this particular storm had wicked weather at 50,000 feet - or something to that affect...
They were transitioning what is known as the "inter tropical convergence zone" or the ITCZ. This is where trade winds from the northern and southern hemispheres converge. This convergence often results in very violent convective weather. My guess is weather wasn't the only factor, though. Usually, a crash is caused by a series of events that stack up on each other to cause the crash. All too often the last item in the stack sadly is pilot error....