This is not news. As a retired college teacher, I have been tempted to express similar criticisms over the years. But do agree the WTF is a just another sign of our declining culture.
Maybe it wasn’t the teacher. I was taking Math 101 as a college freshman. After a big exam the prof had brought the graded exams into the classroom...and left them on his desk. Class didn’t start for another hour.
Some practical joker spotted them and with a red pen added comments suitable to the grade. “Outstanding!” or Excellent!” went on exams with A’s or B+’s. “Study more next time!” or “You can do better than this!” for C’s.
D’s got “Just scraping by?” or “This will mess up your GPA”
F’s got both barrels: “You stupid jerk!” or “See you in summer school, you idiot!” or the classic “Why don’t you flunk out now and beat the June rush!!?”
Needless to say, the D’s & F’s called home and the dean’s office got some pretty angry phone calls. The culprit was never found.
;^)