> I got into the position where I had to report certain problems, like suspected drug use, gang activity, child abuse, and so on [...] the cynism began to grow on me

The reason for him leaving his dream job was completely localized. There are plenty of ways to be involved in teaching besides being in front of a school class. I see this more as moving away from a bad situation, an unhappy collusion of events that got in the way of his chosen path, not a matter of passion vs day job.