Where have all the good PowerPoint writers gone?

This semester I'm using my fourth textbook for teaching Operations Management. (2 in the US and 2 US textbooks here.) There's one commonality among the texts: The accompanying PowerPoint slides suck. This isn't a problem for me because I don't teach from PP. Unfortunately, our students rarely crack the book and try to survive on what they can get from class and the PP slides.

I wonder if there is a specific reason. Unlike my classes in economics, management, HR, or finance, I can't explain Operations Management in two sentences or less. Perhaps there's something endemic in the discipline that makes it harder to make decent PP slides.