I'd say its primarily because the original purpose of a corporation wasn't shareholder value at the expense of all other things, like benefiting the community,

I'd say its primarily because the original purpose of a corporation wasn't shareholder value at the expense of all other things, like benefiting the community, employee wellbeing. It was supposed to be the responsibility of the employer to take care of loyal employees. The 80s and the age of corporate raiders and activist investors changed that.