What's next? 1:74/76 so that the Q400/E170 can operate single F/A.
There will never be any objection by the Companies. It's squat to do with safety, all about saving a buck.
Just because it has been demonstrated that "it is possible under a controlled environment during certification" to evacuate 50 pax from a Dash 8 or 298pax from a 330 using only 1 or 6 F/A's respectively, doesn't mean it's right or safe.