I have to politely disagree with your assessment. There is a scalebar in the first image to verify that he is drawing the grid to scale and in the others all you have to do is look at the size of the doorways to see that it to is scale. As for the grid anywhere he wants, in the first example you can see he's trying to line it up to maximize its use in both examples and yet fit on the scalebar. Of course you are going to line up the grid to the map. Many people do exactly the opposite when drawing a map and map to the grid. I've already spoken at length about that however. I also don't get your point about scanning. It has a scalebar with obvious units, you can scan that a million times to Tuesday and you aren't going to change the relationship.
I get the feeling that your argument is coming from suffering with the cognitive dissonance his points are causing.
Indeed. That is why many other systems have already adopted metric both from a business perspective and ease of usability. In the system I use, Hero, it uses a 2 meter hex, but I'm thinking that a 1 meter hex makes a lot more sense. Of course I'll have to multiple all distances by 2 if I use the grid as my guide but that is pretty much a no brainer.