Why? What I've heard is that if the pilots know how to disable the pitch correction, the plane won't fight them in the event of a sensor failure and they can land safely.
If they had known that MCAS is disabled for 15 seconds by pilot trim inputs, they could have saved the plane. Toward the end of the flight they went off-book and re-enabled auto trim, blipped the trim a few times and 15 seconds later MCAS jumps on and dives them into the ground. All they needed to do was keep making small trims.
I understand it as "if they were able to consistently, all the time, until they land, fight the plane which was trying to kill them every 15 seconds turning the nose to the ground, resulting all the time in even harder position (due to the forces involved) they would..."
Flying death trap indeed.