Questions regarding poverty and recessions are better in the domain of political scientists and ethicists. I agree economics has failed to live up to its promises in these respects.
However, the discoveries of economics cannot be ignored. Can we ignore supply and demand? Can we ignore trade theory? Game theory has already been helpful to computer scientists and has allowed us to create auctions useful in distributing resources such as frequencies by the FCC.
What you are referring to is the Tragedy of the Commons which is a well known scenario that is not so simple as you may think. For example, the Coase Theorem shows that under particularly strong assumptions "ownership" can lead to a good outcome as you described.
The problem arises when you relax the assumptions and then you can observe interesting results showing public ownership many be optimal. This is not "rose tinted glasses" but simply applied economics.
Economics is about understanding how people make decisions, then analyzing what situations bring about optimal results. But if you'd taken a class in Economics, you'd have known that. =)
Psychologists study how people make decisions and economists usually assume individuals make decisions "rationally" to the dismay of psychologists. Economics is about how people respond to incentives, but if you'd taken a class in Economics, etc.
In the sciences, we are now uniquely priviledged to sit side by side with the giants on whose shoulders we stand. -- Gerald Holton
