The fundamental issue with the decision not to evacuate before the situation becomes life-threatening is by the time it IS life-threatening, you have lost valuable time to get everyone off, alive.
We all know the certification requirements mandate a full 777 be capable of evacuation within 90 seconds with half the exits blocked, but how realistic is that with panicking passengers who insist they take their carry-on, or their wallet/passport/packet of smokes that is in their carry-on in an overhead locker? Not very.
It worked out this time, the investigation will show us why that was, but to automatically assume the "it's not dangerous enough, yet" mindset is in itself, inherently dangerous.