I understand. It's just that most accidents have not just one cause but a whole chain of them. Something small happens that causes the pilots to be distracted trying to fix it, meanwhile ignoring the elephant in the room or forgetting a 'routine check'. The flight deck isn't always a relaxed place and this is when these things can get out of hand so easily.

This kind of mistake has been made so often and lives have been paid that I find it crazy that it's still being proposed.