Everyone got them, and we're all spinning them to the point of were you could hardly hear the teacher talk.
The problem is most people who use them don't have anxiety problems. Also apply a little WD-40 to make your fidget spinners quite. Parents got pissed, and had the school ban them for people who don't actually have anxiety.
TL DR: They can be a huge distraction in class which caused a significant drop in grades.