The point of doing it with no EC is to determine what the programming inherently will do, so that folks can get an idea of how much EC to crank in...to set a baseline. After all, Nikon's Matrix metering (or Canon Evaluative) automatically puts in some mysterious 'fudge factor', but the user is certain not advised anything about the logic (at least not by Canon...does Nikon?)... while primary AF zone gets priority, the surrounding AF zones get factored in by some mysterious amount. That is exactly why a number of folks call matrix metering 'unpredictable'.
You might know how much EC to crank in, but what about the poor person who is stepping up to an SLR from the point and shoot? This is a way of imparting some level of understanding of how the camera behaves, without intervention.