Liberals see the free market as a kind of optimizer run amuck, a dangerous superintelligence with simple non-human values that must be checked and constrained by the government—the friendly SI. Conservatives just reverse the narrative roles.
I like this analogy. So basically, how do you want to balance the power between your two overlords, one much much smarter than you but with non-human values, and the other much dumber than you but with human (mostly) values.
Typically, as long as the expense is deemed prudent by regulators, utilities are permitted to ‘rate base’ the expense and earn a return on investment. If PG&E think it’s politically possible to increase expenses by $20-30B because there’s a good narrative to offset complaints of rising utility prices, it’s the selfish thing to do. The times that require strict scrutiny for investor-owned utilities is when they jump on the bandwagon of a politically popular spending proposal (wise infrastructure investments comes from experts getting the politicians on board, not politicians getting the experts on board).