Organfreak;
The excellent link you have provided discusses important aspects of pilots who are non-instrument-rated flying in, or into poor visual conditions. One must believe the instruments at all times because the alternative under some conditions is a loss of control.
You are right, most pilots are indeed familiar with these things...it's drilled into all pilots from very early on in ab-initio training/testing/licencing process.
Some may recall the John Kennedy Jr. accident in which control was lost at dusk, a time of day when the horizon is poorly defined.
Put bluntly (but not overly-dramatically), a non-instrument-trained or rated pilot who enters cloud or continues to fly in deteriorating visual conditions, once entered, has about a minute-and-a-half before the
spiral dive develops. The way out is to immediately level the wings but if one has no horizon and doesn't know how to read the artificial horizon instrument or attitude information is missing (displays blanked), the dive will not be stopped.
Not among the accidents listed in your link is the
Gulfair A320 loss-of-control accident at Bahrain in 2000. Of particular interest is the "
Appendix E, Perceptual Report". Also not listed among these accidents is the Afrikiyah A330 accident at Tripoli which some have discussed these same phenomenon. But we'll probably never know given both political and infrastructural problems which began with the recent civil war in Libya around the time of the accident.
In considering the notion that has been expressed regarding AF447 that all displays were blank, (no information displayed to the crew and not just a missing speed indication for a half-minute), almost certainly the result of loss of attitude, altitude, vertical speed, airspeed, heading etc (on a cloudy, moonless night) would have been a high-speed spiral dive and an extremely high speed impact with the sea. We know that such is not the case.
It isn't direct evidence of course but given the way these things go it is again a reasonable support for the view that the PFD/NDs were displaying most if not all their information except for the CAS.