Complacency is the rational response to current circumstance, where Fed, PPT, etc., will intervene to protect the status quo.
The only real threat will come from the unexpected, which is, by definition, unpredictable.
It will take some unseen, undefined "X" factor to overwhelm all efforts of the stabilizers, one of sufficient consequence to force a shift in circumstance and, consequently, force a shift in perspective from complacency to panic. Until then, in complacency lies the path of least resistance -- and, therefore, profitability.