99% of the time it seems they're not wrong, despite control engineering being a pretty large area of research.
http://www.ecircuitcenter.com/Circuits/op_pid/op_pid.htm
https://www.nutsvolts.com/magazine/article/the_perceptron_ci...
http://www.ecircuitcenter.com/Circuits/op_pid/op_pid.htm
https://www.nutsvolts.com/magazine/article/the_perceptron_ci...