And there in lies the stupidity of our whole situation.
You are at 6000ft, so 20nm give or take a bit from the airfield, you are flying the star and can see the runway.
The forecast i.e. the prediction of what the computer models reckon the weather will be like (because the BOM has removed humans with forecasting experience from the equation pretty much) says an alternate is required.
Do you bug out to canberra to “stay legal” or do you use your ability as an authorised met observer to say “i can see the runway and i can see the surrounding weather environment (no great wall of showers about to cross the runway or approach path for example) and i am going to go and land at my destination”
Fuel policies, CAR234 and met forecasting are a means of risk mitigation intended to obviate the need for some poor sod to plonk his/her aeroplane in the field/ocean/multilane highway because they didnt consider the weather.
There needs to be some measure of common sense (yeah I know, that isnt all that common) and use of the captains decision making perogative not blind adherance to rules even when they produce a less than optimal result.
If you go and fly a 747,380,777 or other such large people mover, the decision making becomes more challenging as the ability to find other airfields that can accommodate your aeroplane is reduced.