It seems that in the past things where somewhat different. The sole focus on maximizing shareholder value is something that happened quite recently. A lot of people trace that to Jack Welch who took over General Electric in the 80's
I highly recommend https://www.amazon.com/Man-Who-Broke-Capitalism-America_and/... if you are curious about it.The book documents well the transformation which gave us the modern version of US companies.
Some remedial reading for you:
https://www.amazon.com/Man-Who-Broke-Capitalism-America/dp/1...
"You Can't Order Change: Lessons from Jim McNerney's Turnaround at Boeing" - December 26, 2008
https://www.amazon.com/You-Cant-Order-Change-Turnaround/dp/1...
Probably mostly of the "do the opposite of whatever this guy says" variety. ;)
The top review on this book says:
This seems like a good follow up book too:https://www.amazon.ca/Man-Who-Broke-Capitalism-America_and/d...