The cost, the syllabus and the term "night rating" implies a whole new set of priviledges, and that is the problem with it. The US system of making it a small part of the PPL is more sensible, rightly implying it is a small part of the day VFR syllabus designed for leaving a little early, or getting back a little late. The fact more night VFR only pilots don't end up in a hole 2km upwind is because most people are sensible enough during the training to realise it's a poor man's instrument rating and either are good IF pilots anyway, or don't use the rating for entirely-at-night flights.
Mcgowan -- what do you mean "the use of instruments is really for an emergency"? Where are you looking after rotation?