Reducing our decisions to dollars and cents keeps us focused on the impacts of our choices to ourselves, financially. It distracts us from the impacts of our choices on other individuals, or on our communities more broadly. Recognizing that those others are of value -- that they have interests that matter, too -- is kind of at the heart of being an ethical human being...
I'd really like to nudge myself, and those around me, to a place where we make more of our choices with a mindfulness about how those choices change the choices available to others (and to ourselves down the road). I don't want it to fall to our water bills to make us be the people we ought to be.
I disagree. Sure, insofar as we are acting qua citizen -- engaging in public debate, political advocacy, voting, etc. -- we should be guided by concern for the general welfare. But we should prefer to avoid needlessly burdening private individuals with additional concerns in their everyday life.
Benign spontaneous order is the ideal: far better to set things up so that ordinary thoughtless actions will tend towards the public good without any special effort or knowledge required on the part of the individual. As I wrote in an old thread:
I'd be delighted if our societal systems were so well-designed that people rarely needed to consider impartial moral reasons at all in their daily living. There is plenty of room for that in the public sphere, and it seems a more personal focus (on one's close relationships, etc.) would do more to enrich the private sphere.
Besides, it strikes me as perverse virtue fetishism to oppose effective institutions (e.g. markets) on the grounds that their good results emerge without requiring private virtue. Policy should be geared towards actually improving the world, not getting people to try to improve the world. (Cf. opposing safe-swimming flags at the beach because they reduce the opportunity for heroic rescues!)