One of the fundamentals of a Safety Management System is to risk assess literally every single aspect of every operation. Reducing accidents begins with the removal of every 'high risk aspect of an activity. Where removal is impractical then some form of mitigation must be employed.
I used to spend my winters flying single pilot day and night doing offshore shuttling 185 miles from terra firma in my trustee Bo 105. We don't do that any more. Why? Flying single pilot could be removed from our service inventory and the risks reduced. The cost-benefit was judged to be worth the candle.
We are humans, we learn from our mistakes and if we possibly can we don't stub our toes on the same rock twice. We dig up the rock or change the route. You can - and I know because I and many other pilots out there flew successfully at night in both singles and twins - on our own. It's not rocket science but it is high risk.
Literally, you pays your money and you takes your choice. It is not about well trained or not well trained ( I have lost some very competent chums at night, in a Sea King, in a Wasp and in an S76). It is simply harder to do the job safely at night and mistakes can have more serious consequences.
You are not 'wrong' if you operate single pilot/single engine at night. You are simply taking a bigger risk. If the cost-benefit equation is in favour of that modus operandi then fine but lets be honest. Does the customer get the benefit of a full explanation of the risks associated with 'economy' as compared with 'de-lux'. You should be able to guess the answer because there are not many single engine single pilot airliners out there.
Why not? When we make decisions on behalf of others we tend to err on the low risk side of the equation but when we judge risk for our own group or ourselves it is easier to feel close to the impact of price and therefore we can minimise the impact of risk and focus on other elements of the equation such as cost, enjoyment, time saving and excitement. Thus regulators say two engines at least and two pilots at least when you take the family to the Costa Brava yet, for some of us at least, given the opportunity to do the same trip in a 206 we would jump at it, even if it involved a bit of night flying and our night-rating was barely in-date. But would you send your wife and children in the same helicopter if you weren't driving and you had no idea about the person that was?
G.