That woman sounds like a sicko. Either that, or she is over-worked and simply overreacted.
I've always really hated the "those who can't do, teach" comment people use as an insult. Most of the people who say snarky things like that don't have what it takes to be a teacher. My high school teachers ranged from stellar to stupid, but I have to think about what they sacrificed for us that those in other careers don't. While we were preparing for our IB/AP exams, my teachers would devote nights and weekends tutoring us, giving us extra tests, and paying for books and supplies OUT OF THEIR OWN MONEY. During the summer, a lot of the teachers are club/class advisers, teach summer classes, and spend the same 8 hours in the classroom as they do when class is in session.
Also, when one factors "median teacher salary", you're usually averaging ALL teachers, whether they're starting fresh out of college or have a Ph.D (as is what some of my math teachers did to make extra money). Is 50K really that good for someone with a doctorate in education? Where I live (which is hardly a poor/innercity area), bachelors' level teachers start out at about 35 a year, which is nothing when you consider the cost of a house.