Indeed; I recall reading some numbers a year or two ago, showing that 2/3 of the NPPL applicants were PPL holders who either failed or did not wish to continue their CAA Class 2 medical.
In that respect the NPPL was a disappointment to those who wished that it would revitalise the private pilot scene.
It is obviously beneficial for the medical side alone, but whether one should do it if one can pass the Class 2 medical is a good question.
A more cynical view is that the NPPL was pushed by the flight training industry who wanted a lower priced product on their training price list. This was achieved but for a given level of competence it won't cost any less. Very very few pilots do the PPL in the 45 hours minimum; those that do are either very young or have been benefitting from unlogged flying with mates etc.