They are the intermediary by which scarce capital can be allocated to productive uses, thereby making society richer.

The supply of credit became infinite, utterly divorced from its traditional role of allocating scarce capital.

Perhaps, too, the easy monetary conditions since 2008-09 have impeded the process of creative destruction, so inefficient companies remain in business and use scarce capital.

They serve a useful purpose for the economy by enabling investors to diversify their wealth and directing scarce capital to businesses that can use it productively.

The answer depends on the balance between risk and reward, and how much scarce capital the government should be willing to lose on a risky proposition.