If you were flying your 767 into YSSY and 16L was the only option, would you divert to somewhere with a 3km runway?
When first officers are coming up for command you often see them using this kind of logic. An all or nothing kind of logic that seeks rules to keep one safe. It is not a bad thing, it means they have recognised the responsibility approaching and are setting about making sure they have all their ducks lined up. A few months of upgrade training helps them realise there are few decisions where all the inputs act in isolation and the decision is simple.
If everyone required the long into wind runway then every day would be a single runway day and we'd all be screwed.
Again the logic is too simple and doesn't reflect real life.
Situation A) CAVOK wind 350/5
Most people would be happy to land their 737 on runway 27 .
Situation B) CAVOK wind 350/45
Very few people ( any?) would land their 737 on 27
What this means is that somewhere between situation A and situation B the trade off ( commercial efficiency v's safety) becomes a bad deal. The system has decided that that point is the point where the crosswind exceeds 20kts or the downwind exceeds 5 kts on a dry runway. That's great , it is absolutely necessary to have rule based limits to prevent the small % who will make poor ego based decisions. Every Captain will have a slightly different assessment of where that line is though depending on many different factors affecting the particular flight and that is what they get paid for. In short, every day wouldn't be a single runway day, and if a day did become a single runway day that would be because all the inbound Captains decided that that was necessary for safety.......who's going to tell them they are wrong?