Hosting a long term game of freeciv was essentially the catalyst for me transitioning from math teacher/trade union official to web developer, via making some web apps For the players involved.
I understand things change, income is different between jobs. I am not passing judgement on the fact that you transitioned away. It would be awesome if teachers were paid as well as a web dev.
This comment sums it up => "I'd consider it if I didn't need a four-year degree.", (https://news.ycombinator.com/item?id=20101794)
The type of work, though, and skills required are quite different, regardless of that they technically both develop and involve 'technology'. Semiconductor lithography requires a pretty exciting mix of skills starting with plain physics (classical and by now a bit of quantum optics), materials science, mechanical engineering, data analysis/science, software engineering (both for simulation and analysis of production of lensing systems), and I'm sure I'm missing half. It is quite different from "writes software for a software company", which is the framing I had interpreted from the comment I originally responded to.
1. Pay
2. Professionalism - all of the teachers I saw and talked to under 65 were treated like dirt, and were micromanaged instead of being treated like professionals
3. Barriers to entry. By the time I got my Master's and decided I'd rather teach high school than spend several more years getting a PhD, it was financially impractical for me to go back for more years to get a teaching degree. It was also very difficult to find internships and open positions. One guy I know who did a straight teaching degree interviewed almost a HUNDRED TIMES despite doing incredibly well in his program and student teaching at a prestigious high school.
I'm sure the kids are doing fine without me, but I had stellar reviews from every kid and parent I ever worked with, and from professors I TA'd for. People have told me my whole life I should be a teacher (came up again just the other day with the guy I was pair programming with). I'd happily take less money to be a teacher, but when you add in factors 3 and especially 2, it just isn't worth it to me. I'm not going to suffer a bunch of professional abuse and take a financial hit to boot to do something that my society doesn't seem to genuinely value.
However, you might be interested to know that the most successful business in my neighbourhood actually operates an online high school. A friend of mine in another city also operates an online high school and seems to be doing quite well for himself. There appears to be a large market for such services.
Especially if you also have web development skills, the internet provides a platform to be a teacher independently, resolving the second and third points. The first point probably depends on your business skills. However, seeing how well that aforementioned business in my neighbourhood is doing, the potential upside is huge.
As a teacher, I was working 70 hr weeks to get lesson plans in place and to grade work. Summers were booked for summer school. Every minor "vacation/break" was filled with catching up on everything. I worked with socio-economically challenged inner city kids whose families (generally) saw no benefit to an education. The pay was terrible. After 5+ years and if I were not the sole income for our household, we might have been able to eek by. As it was, we were in a debt cycle that we could not have escaped. I would never have been a home owner.
After becoming a software developer, in my first year, I made as much as a teacher with 20 years experience and a doctorate. Fast forward several years, and I out earn superintendents. I can actually have a mortgage and plan vacations with the family and help my kids with expenses.