My highschool physics teacher had a similar story, he was one of best teachers I ever had. I went from disliking physics to becoming a EE major in college. Doubt I would be where I am today without him coming in at the right moment in my life.

So, yes, a good teacher could inspire 10+ others to make spacecraft, tech startups, etc. Maybe the ROI for humanity is greater if that teacher stayed as an IC in their field.