Because people raved about those moments of great effort and incredible athleticism and didn't look 'under the hood' her freshman year. Diamond shot more than any other player at UNC (220 more shots that the #2 player) and shot more threes than any other player and she was shooting similar percentages to this year (.424/.279). The rest of the UNC team shot .450/.336 and there were 5 players shooting significantly better and five players shooting threes better than Diamond on that team. She had the third highest number of assists on the team, but she was the only one of the three to have more turnovers than assists - her A/TO of 0.75 - the rest of the wings/guards had an A/TO of 1.19 and the team had an A/TO of 0.89 All of her percentage statistics were below the team average for those statistics. She had a gaudy scoring average but she was a very inefficient shooter. UNC was a free flowing offensive team, TN is not, so what you see looks worse this year, but it really is a continuation of what came before.
In a freshman you look at all the excitement and forgive the other stuff, as a third year player you are happy for her that she is able to play 'her style' of basketball, and thankful it is for someone else's team!
On Edit - she is actually shooting a higher percentage than the rest of the team this year at TN so comparatively she is doing better this year than her freshman year. (That does not say much for the rest of the TN team!)