"The lesson to be learned from quantitative easing, zero-interest rate policy, and the bubble advance of recent years is simple: one must accept that there is no limit at all to the myopic speculation and self-interested amnesia of Wall Street. Bubbles and crashes will repeat again and again, and nothing will be learned from them. However, that does not mean abandoning the information from valuations or market internals. It means refraining from a negative market outlook, even amid extreme valuations and reckless speculation, until dispersion and divergences emerge in market internals (signaling a shift in investor psychology from speculation to risk-aversion). A neutral outlook is fine if conditions are sufficiently overextended, but defer a negative market outlook until market internals deteriorate."
Basically, this can be read as a complaint about how distorted the financial markets become when we rely on the Fed to protect us from recessions. If Congress would do its job, and provide sufficiently large deficits to absorb the productive capacity of the modern economy, then there would be no need for the Fed to engage in such extreme behaviors, and we would not see this kind of distortion in the financial markets.