What about bond holder value?
Bonds can offer value to both savers and investors even paying little or no interest. This is because bonds are issued to pay for things that contribute to society and the economy, that would not have otherwise been performed, had the bond not been issued. Absent the opportunity to earn that money in the first place, the money people save in bonds would not have existed at all! This is not a matter of people merely deciding where to put their money, but even having any money to save in the first place. The real opportunity cost is not in terms of poor return on accumulated money, but rather reduced sales, unemployment, and other forms of real idle resources. As for savers and investors, an opportunity to earn money is judged on the price offered when it is earned, and then savings is just where ever the leftover money ends up, after people have purchased all the goods and services they need, as well as other investments. Note that buying goods and services can be considered an investment just as much as lending or corporate stocks. Savings is what people do with leftover money, or a stock of money people accumulate in anticipation for large purchases or other future spending. Bonds are issued to serve as a place for people to park their leftover money!
Public investment is different from private capitalistic investment, in that the value of the investment should be measured not in terms of flow of funds, but in terms of net benefits to the public. Public investment can increase the value of both public and private balance sheets. Without infastructure, courts, regulation, and other public services, private companies would face a much more difficult challenge in engaging in profitable enterprise.
Because public value is not about revenue in the form of taxes collected or exchanged for services, it requires completely different considerations.
Private companies are dependent on sales for their operation, but public entities play an entirely different role. Their job is to pay for things that we as a group benefit from, but not as individuals. It is antithetical to principles of capitalism, trade and markets, to try to suppress this role. It ignores the huge relevance of externalities, both positive and negative. Many of the things that are worth doing that are a matter of shared interest, and can only be effectively accounted for as such, backed by public institutions.
Share holder value is maximized by effective operation of a private company. Sometimes short term gains are actually a long term negative. The same is true of public value. Bond holder value is one way to measure the efficacy and benefit of public services and enterprise, but it is not the only consideration, which is why it should be supplemented by effective democracy and other forms of political accountability and representation.