I hear you. US collectors, just like ancient collectors, pay more attention to the obverse than the reverse. I was thinking about that as well, so 63, 63+, or 64 in my mind would not shock me depending on the grader that day.
I would have thought it would have gotten a gold bean, not just green. Reverse too nice for the holder IMHO.
But why? Never made sense to me why one side was more important than the other. Not saying you aren't right HOW they do it, but asking if its CORRECT to say that. I could understand this mentality if the obverse was different rulers, or the portrait changed over time. However, this is a make believe person than never changed in the course of the Morgan run. Why should one side be more important? I would postulate it should be 49/49/2 Obverse/reverse/edge percentages to be fair.