I hardly see that as a counter. Both Kling and Krugman are right! The government is a ponzi scheme, and lots of the financial sector has been ponzi-like, too!
(And a point that Kling might make but Krugman tends not to: much of the financial-sector ponzi-ism was propelled by government policy, which inflated the housing bubble with tax benefits, Fed-lowered interest rates, government-sponsored mortgage-underwriting, and regulatory favoritism for dubious mortgage-lending. And policy which then further insulated finance institutions from existential risk with the implied promise -- now delivered -- of giant bailouts.)
