I've used that data on numerous occasions for a couple of years now and checked for accuracy against specific cadets I know well. While it is largely accurate, the data does share the same problem of all large data bases - input/transfer errors. In particular, I find the USMAPS attendance data highly suspect - to the point that I do not uses that column at all. It is unlikely that appointees with such low test scores would receive the academic "Q".
A more germane use of the data is to compare test scores to academic GPA. There are cases for both arguments - low test scores followed by an expected low GPA and low test scores followed by an unexpectedly high GPA.
I believe in merit and do not like special consideration for athletes, legacies, minorities, etc. However, we live in a world of special consideration and USMA needs to operate in the real world along with Harvard, Stanford, Michigan, etc. West Point does this quite well, with the majority of appointments decided on a competitive basis - arguably much better than civilian universities.
Admissions tracks those who receive appointments with special consideration and out of order of merit by identifying those whose WCS scores, although qualifying, are likely not high enough to win appointment on a competitive basis.
From a briefing to the Board of Visitors for the Class of 2016:
Athlete: 218 total, 125 with WCS < 6000
Black: 103 total, 45 with WCS < 6000
Hispanic: 116 total, 44 with WCS < 6000
Women: 187 total, 41 with WCS < 6000
USMAPS: 197 total, 92 with WCS < 6000
Note: Appointees can fall into more than one group - several of the Black, Hispanic, Women and USMAPS are also athletes. Athletes are clearly the most advantaged category, but there are many athletes win appointments with no extra help.