Modern jets are completely "fly by wire", and if there was an electrical failure with accompanying engine and hydraulic failure - inevitable with a complete electrical failure - the plane would in just a few seconds, lose stability and go into a high speed spin. The skin and even airframe - certainly the wings and tail - are not strong enough to withstand that kind of force, and the plane would literally SHRED as if put through a meat grinder on its way down to the ocean surface. Scattered wreckage is precisely what you would expect to find, and is indeed, what has been found!