Let me ask you a question, with respect to the winning team’s point guard. Should she diminish her skills - and her attractiveness to any college recruiter - by not playing her best?
If the coach altered his game plan to avoid intentionally running up the score - and I understand from several posts here that he did - then he fulfilled his duty to sportsmanship. If he further didn’t allow his players to demean the opponent (and I have not heard he allowed this in any way), then he has instructed the girls on his team well in sportsmanship.
The “they let up at 100” comment was from the opposing coach. In my experience, the girls of the team may have chosen to set that as their own goal, at which point they decided to let up further.
I do not have issues with this coach, personally. His sin appears to have been his public defense of his team (and himself). The school, however, also sinned by impugning their own team and coach publically, without having addressed the situation privately first (apparently).
Again - I am at the point now that I just don't know who to believe.
But if, say, after the coach called off the full-court press [when it was 25-0], the point guard was swooping in and stealing the ball just as soon as it advanced to the mid-court line, then yes: After about 50-0, that's inappropriate behavior.
Sometime around the 50-0 mark, the coach should have ordered his girls back beneath the basket, and told them that their zone was to remain in the lane to the greatest extent possible, and that under no circumstances was the defense to extend beyond the 3-point line.
On the other hand, if the point guard was making these steals at the [defensive] foul line, and then dribbling three-quarters of the court for the layup - well, I guess there's not much you could do about that.