I get wanting more data, but I don’t understand how it would be lost. If the craft burns up on re-entry due to many possible factors (Angle of descent, speed o

I get wanting more data, but I don’t understand how it would be lost. If the craft burns up on re-entry due to many possible factors (Angle of descent, speed of descent, uncontrollable trajectory, etc, etc) any evidence of faulty components would be 'disappeared'.