Troll or not, this topic needs to be discussed. I'm not saying Moritaka, exclusively (I haven't seen the overgrinds issue in person, after selling a Moritaka, and two more still to inspect). However, this issue needs to be cleared up, in how people are perceiving it. To me, a true overgrind is something a) unintentional, b) one that will cause issues on the primary bevel - immediate or not, and c) a pain in the ass.
As far as I can best explain the issue, it is a low spot that is deeper than what one would normally thin to on the secondary (sometimes primary, but that's an easy fix) bevel. It causes a hole when the overgrind is so deep that it either goes into the other face of the knife (think of the knife as two faces - a left and a right - when looking down the spine and splitting it down the centerline), or when it is almost into the other side, and is so close that it will not allow an edge to hold on that section once the sharpening has hit that spot. For this, think foil thin, on one blade face.
They're very hard to see, because the knives we are discussing are so thin that it can be an overgrind of nothing more than a hundredth (or two) of an inch. However, the end result is a totally unusable position along the blade, often extending up towards the spine, rendering that area useless for many mm's, even a cm. thus, you'd have to take a gyuto with a heel height of 50mm down to (for example) 40mm, just to make it potentially useable. At which point, you'd have to regrind the bevels, and create an entirely new knife.