I'd say that in order to really have a worth while PPL, then the PPL should include 5 hrs instrument and 5 hrs night - could be run at the same time though. The reason is that anyone in the world can embark on a VFR only flight, only to get caught out and then make a bad decision and end up killing someone. The night thing would mean we could do away with the silly NQ. I wouldn't dream on embarking on a night cross country myself without any insturment training.....(or even crossing long sea crossings), and it may be quite useful to do some of the instrument stuff at night...
5 hrs is about the minimum to get to grips with basic attitude instrument flying with no frills - enough to keep one alive IMHO.