they might be better now, but before I made knives 2 years ago, I had something sharpened there and it was ok...but I wasn't impressed either.
I believe he uses power sander which I don't recommend.
also the philosophy of they remove as little metal as possible is in general fine, however it depends on the knife, the edge, and the geometry
If you just want it sharp, then ok, but if you want the knife to cut, then you have to thin down the geometry and that means removing more metal from the bevel sides.