I think people underestimate a teachers salary. Yes, it seems like you are under paid, and to an extent you are, but there are certain financial benefits to being a teacher. A great pension being the most overlooked.
Most teacher pensions allow you to get close to your ending salary at full retirement.
Lets say you are a 62 year old teacher making 70k a year (will be more or less depending on state/school district, etc). To be able to spend 70k a year in you would need to have saved around 1.75 million. That is over stating it some. In the private sector you can get Social Security. If you had been making, lets say, 100k at retirement you.ll probably get around 20-24k a year at 62. So you only need 50k or so from your savings. Or about 1.25 million.
It would probably take you saving 10-20k a year to accumulate 1.25 million after 30 years (10k at start, building up to 20k at the end.). 20k on top of 70k takes you up to 90k.
On top of that, you are only working 3/4 time. You get about 4 months off per year, and your days end at around 3. Yes, some teacher work after that, but a lot don't (just like I worked more like 45-55 hours a week most of my life as a software engineer, but some do not).
Teaching is a good career choice for someone willing to sacrifice today's earnings for an relatively early, stable and secure retirement and more free time.