In an ultra-low interest rate environment this virtue becomes a challenge. And this environment is here to stay. Fundamental economic factors as well as central bank guidance indicate that low rates will persist for quite some time. 2/5  BIS central bankers' speeches  Finally, there is regulation. Many complain that regulation has become tougher.
The GFC surfaced the “not-so-apparent” changes in the nature of macrofinancial linkages, including, among others: 1) the strength and causation of the feedback loop between the domestic real economy and its financial markets; and 2) the importance of the risk-taking channel of policy transmission. These linkages were not much considered or thought of as systemic, but they (in reality) are.