This topic just shows why judgement is still so important in aviation. Whilst its always good in training to give students some pretty firm boundaries so they can develop their experience I am extremely frustrated with the push to put black and white law to every situation for people flying the line. The earlier post of 'it depends' says it all. There are so many variables even when flying the sane type into the same port every day that we must use our judgement to make thus type of decision.
If you flying a medium or heavy jet into a normal port (3 degree app and PAPI) it's not a normal view and you have to consider how you got here. ie ham fisted handling or were you left high by ATC and you have been working on fixing the problem, are in control and both pilots know what's going on. 'I saw four whites so I went around' is a pretty lame excuse but 'the approach was getting out of hand (even if not technically unstable) so I felt the a missed approach was the best course of action' should be fine with any reputable operator.