Except that the classifier stages that bump those B shooters eventually to GM are by and large "stand and deliver" tests.
I totally agree on the added complexity of drawing from concealment, especially if we're talking about something other than the "shoot me first" IDPA vest. And if you take away an Limited M's 2011 and hand him a G19 he's going to suck for at least a few minutes. We can all agree with that.
However, considering that the OP first said it was a few GM's who couldn't complete a FAST drill in under 9 seconds, then said it was a D, a C, and an M, and so on, I'm not going to be too surprised if next he says it was really 6 seconds - and the M was drawing from an ankle holster.