In that time, ratings were not restricted, IE: everyone in a squadron could be rated at the highest level in all categories and overall.
In the mid '70's that was changed; they set percentages for each group to be rated. Only so many % could be the top, so many % the next block down etc.
However, at Kerry's time there was no restriction. Thus, if you were a true "fastburner" you had a "firewalled" OER or FitRep. That means EVERY block was rated at the highest level and you also needed some certain "codewords" in the written comments by your evaluators. For example "promote at the earliest opportunity" was a necessary comment for a true "fastburner".
So, when you look at Kerry's reports and see blocks that are NOT all the way to the left, you are basically looking at the "kiss of death" when it goes to the promotion board. Same with his written comments; they lack the necessary "zing" to get promoted.
From the ones I looked at, you're looking at average FitReps.
Before you ask, one of my "additional duties" in my USAF squadron was reviewing OER's before final submission and "pumping up" the ones that the CO felt deserved promotion.