"Children of the Magenta" is an aviation-specific reference to the generation of pilots trained to rely on automation beyond its point of utility. It was coined in 1997 by American Airlines captain Warren Van Der Bergh, and he was referring to American pilots. For an example of how you get "Children of the Magenta", some airlines require pilots to use autoland whenever available, and never hand-fly while on the line. Thus pilots get trained to follow the magenta guiding lines of the automation. This leads to situations where, confronted with an automation failure, the reaction of the pilots is to try to restore automation. Now, automation fails for a variety of reasons, but chiefly because the aircraft is in a situation where automation can no longer do the pilot's job, for example, a sensor failure or something broke.
The fact of the matter is, while we all want a pilot like Sullenberger or Liu Chuanjian up front, aircraft have to be flyable by even the worst pilots. The Lion Air MCAS problem should have been resolved when the first flight crew to encounter it turned around and landed at their point of departure. Instead, probably due to commercial pressures, they continued their flight with manual trim and the stickshaker going continuously until touchdown. The next crew fought for a bit, then one of the two people up front did the worst thing possible, repeatedly: tap the trim button just enough to reset the MCAS for another cycle of nose-down trim. The Ethiopian crew apparently knew what the problem was, but disabled electric trim before neutralizing loads. Then they found themselves unable to mechanically trim the aircraft and unaware of the procedure to unload the plane.
One of Boeing's responses, especially to Congress, has been to blame the pilots. Yes, the pilots didn't perform outstandingly in these cases. And maybe they were "Children of the Magenta". Yet the core problem is one of bad design, a bandaid on a jury-rigged solution to keep a 50-year-old design in the air so that airlines following the Southwest model don't have to train their crew on two different types.
Compare to "Children of the Magenta" cases like the Colgan flight outside of Buffalo, where the pilot reacted to the stick shaker by pulling back, even overriding the stick pusher (training to the FAA test emphasized minimizing loss of altitude in a stall), or the recent Superjet crash, which at this point looks like a pilot was unfamiliar with flying the aircraft in a degraded FBW state ("Direct Law") and, on approach in a perfectly flyable airplane with plenty of fuel, promptly ignored seven predictive windshear alerts ("Windshear. Go Around" -- the record shows that he did not go around), and killed a lot of people. In those two cases, the part of the automation that actually flies the plane dropped out, putting control in the hands of the pilot and, at some point, providing strong instructions one what the pilot should be doing. In both cases, the flight crew proved so unable to fly the plane that they even ignored the sage advice of the machine that was trying not to get them killed.
Yes, racism plays a role here, especially as to how Boeing's spun the issue. Asia and Africa are huge growth areas for aviation, and that's where Boeing is selling a lot of planes, especially ones like the MAX that are designed to cram a lot of passengers into a small space and carry them at a fraction of the cost. But the Chinese were right to ground the plane immediately regardless of GP's explanation. "Children of the Magenta" refers to a training culture more than a national or ethnic one.