I'd argue the problem is more to do with parents. The teachers didn't raise a bastard, his parents did.
But if you walk off your job working with children because a child was rude to you, maybe you don't need that job that badly.
Yes, if you are so fragile that you quit your job because a child disrespected you, then you really don't deserve much respect.
Of course, we don't know the whole backstory. Maybe this janitor was a creeper who the kids all hated. Maybe this kid comes from a troubled home and was acting out. It's why I don't take anything at face value.
I was born in a very working class background. My dad was a sheet metal worker (who died at 56 because he got to suck in asbestos at work all day for 30 years) and my mom was an art teacher at the Catholic Prison Camp I attended for 8 years. (I don't call it a school, I call it a prison camp.) So, no, we weren't wealthy by any means.
So you know what I did? I worked hard in school so I wouldn't "dig ditches". I joined the Army Reserves to pay for college because my parents were too busy being dead to pay my tuition. I worked two minimum wage jobs to afford the rest of it. Then I went active duty for six years after college. And after I got out of the service, I walked smack dab into George H. Bush's recession and the best job I could get was working in a warehouse. I realized that despite my education and veteran status, I really needed more skills, so I went back to school and got them. When the jobs I finally got didn't really pay that well after old Dubya decided to top his dad by REALLY wrecking the economy, I started a side business that grew into something substantial.
So, no, I'm not going to have a lot of sympathy for an underachiever doing a menial job, who quits in a huff because a child was mean to him.