When it comes to flight computers it makes sense to be conservative when it comes to computing power - the goal should be simple, proven, and functional. But when it comes to diagnostics why not use more computing power? As the article states A second electronic system found on other Boeing jets also alerts pilots to unusual or hazardous situations during flight and lays out recommended steps to resolve them. Seems better than flipping through a paper manual when you've only a minute or two to save the plane.