"I remember the quote by an AT&T executive who said that throughout that era he was terrified some corporate raider would realize how much copper AT&T had, and would acquire the company to strip mine the phone infrastructure for short term profit."
That would never happen as PUC's (Public Utility Commissions) across the country would have blocked that move. As soon as someone tried to rip the copper out, PUC's would be asking what they will be replacing the copper with. If thsy said nothing, then you have fines being levied and laws being broken. So there would have been no short-term profit.