You are making heavy assumptions on the composition and math literacy of the HN community, the idea of people not upvoting things they don't fully understand a

You are making heavy assumptions on the composition and math literacy of the HN community, the idea of people not upvoting things they don't fully understand and the difficulty of control theory. I've had this stuff in uni, forgot most of it, and re-learned it during my current studies via thinking about optimization of neural networks and I think both our understanding of things and pedagogy are improving to the point that it's not unreasonable to expect tech-interested recent high school grads to have an intuition, if not a formal understanding of control theory. 3B1B might be the most "to blame" for this, but also just the proliferation of tutorials, making etc. PID controllers are not very complicated, people dig into robotics on their own and find PID might not be enough => voila, they self teach observability, controllability, lie algebras etc.