Just think it through, the captain would always be given the sanction of turning the feeds off. If it is switched on, for 99% of the flights from engine start to shutdown, but switched off for 1% due to technical problems or weather conditions not for public consumption, what would a nervous passenger think when it was switched off? OMG, we are going to die? Much better that it is not switched on to start with, imho. Ignorance is bliss.
Why should it ever be turned off?
Remember that we are paying customers who are putting our trust in your airline to transport us safely from A to B. Why should any weather conditions or other situation warrant the pax being left in the dark? If a situation is ever anything less than 100% safe why shouldn't I as a passenger have the right to know?
If a pilot is not doing anything wrong, why have anything to hide? If you are breaking any rules then surely you need to consider having the rules changed rather than breaking them as this is the start of a slippery slope?
Please remember that whilst sitting at the front you know exactly what is going on, further back there are many very nervous pax who imagine all sorts of events and situations. I am one of those and it is quite easy to adopt the "OMG we're all going to die" mindset for no real reason anyway. The lack of knowledge about what is going on is often the cause of this.