So in conclusion, you CAN depart at night with ONE exterior Emergency Exit light unserviceable provided the AFFECTED EXIT is NOT used for operational reasons, this may require reducing pax numbers as per YOUR DDPG, the mentioned numbers are for a 189 seat configuration.
Just a discussion point guys, and a request for opinions. These kind of rules cause me to question the thinking behind them. I can go along with the idea that the exit may be considered unavailable at the 'planning' stage. We use this philosophy in other areas. However, at the actual moment of an evacuation the exit is perfectly serviceable. There is a strong school of thought that the 90sec evacuation time via 1/2 the exits with no hand luggage is unrealistic. So here is a useable exit, which may be on the good side (e.g. engine/brake fire or collapsed gear on the other side) and the C/A's are told it MUST NOT be used. Meanwhile pax are trapped inside the a/c and perhaps even some perish. That might lead to an interesting court case.
Imagine applying the same logic to an emergency escape exit from a building that catches fire. It would not happen. All exits are used even jumping out of windows. I'm not suggesting that on a/c, but not to use a serviceable door because of a light seems to be not the clearest of thinking and a rule devised behind a desk in a committee room.
Opinions, especially from any C/A's. What would you do with a cabin fire and seated next to an operative door?