The "children of the magenta line" is a real issue in my opinion, but I do not think that it has anything to do with either crash. There is no evidence that the pilots were deficient in hand flying -- that may be a surprising statement to some who have been following this discussion, but "hand flying" doesn't mean "physically crank on levers and wheels to control the aircraft's control surface." That is what the pilots were being asked to do because there was no way to turn off HAL -- all they could do was bypass him by crippling the same controls that they were using and revert to the emergency backup. However, it was not even that simple, now we are being told that the mistake of the Lion Air pilots is that they turned off the power trim system too early and instead should have used the power switches to revert the trim and then turned it off while at the same time blipping it to reset MCAS-- which is what it appears that they were tying to do just before the plane pitched nose down into terrain as HAL came roaring back.
The emergency manual backup wheels that they were expected to use is so disregarded that most modern planes do not have it and was allegedly made smaller in the NEO in order to make space for the display screens. I see an analogy to a modern ship's wheel which is hardly ever touched because everybody uses the hydraulic systems that are part of the ship's autopilot. That doesn't mean that captains are always steering the boat by entering courses into the autopilot or worse, are children of the magenta line, it just means that there is no point to trying to turn a large ship by cranking like the devil on a relic from the days of square rigged sailboats and 100-person crews. If a captain were slow to realize that his NFU (non-follow up control, the way that you use power steering) control was sometimes slipping in a few extra degrees of turn than what he commanded we would not put him in the same class as a pleasure boater whose only experience with navigation is to touch points on the Garmin screen and then hit "engage autopilot." He or she may have been deficient in diagnosing the problem, or deficient in noticing that the ship was headed somewhere other than commanded, but that is an entirely different issue and one that probably relates more to experience.