Contrary to what Tsully tells the aircraft wasn't a huge fireball (otherwise we couldn't see a fairly intact cockpit and part of fuselage on these pictures) but probably the force of impact, seats and luggage crushing the front sitting pax from behind, and the fumes were too grave for anyone to survive. There are other examples.
On photo's, parts of the 1972 BEA Trident crash at Staines looked quite intact, still noone survived this accident, same with a 1974 Pan Am Pago Pago 707 accident. Same with some car crashes when you see (on photo's or TV) fairly decent damaged cars and still all occupants died.
nobody has ever died from hard work, but why take the risk?