OK, but that doesn't answer why? Why is PE about short term ROI at any price? Is it really true that the maximum long-term ROI is by doing it this way? I'm skeptical, and people's intuitions based on their observations isn't very useful.

Maybe this is like the toupee fallacy, and we only pay attention to the ones with this kind of strip mining approach, and we don't see the majority where they run the businesses to maximize ROI in the long run?