To look at it practically, how can one fly at night, unless it's a fair size moon, and few if any clouds?
Unless one has had adequate instrument flight training to be able to fly and navigate in IMC, it is an accident looking for a place to happen, in my view, if someone merely goes by the "in sight of surface, clear of cloud" rule.
I have both a Night Rating and the IMC Rating, and use the latter too, and while I don't have many night hours (about 10, hard to do lots due to airfield closing times around where I am) I have done enough to realise that PPL style flying and navigation is hopeless unless there is plenty of illumination and very obvious ground features.
I think it's great how one can fly around the UK, IFR, it's a unique freedom, but I do think night flying after merely PPL-level training (plus a few hours) is a different proposition.