One of the original ideas behind the NPPL (SSEA) was that an applicant could get his/her NPPL one year, then enjoy flying with or without passengers for a while, before coming back to do the 'top-up' training for the JAR-FCL PPL(A) later.
This doesn't seem to have happened. Of course the training schools make more money out of a JAR-FCL PPL(A) student, so aren't too keen on promoting the NPPL(SSEA).
Industry told us they wanted the NPPL and we've delivered it. The fact that industry hasn't done much to sell it is the problem. Also ORS4 no. 711 (now no. 756) was launched without any RIA, so NPLG is losing revenue to SEP pilots able to use these exemptions with their UK-issued pilot licences who would otherwise have needed a NPPL(SSEA).
At least the NPPL is a far better and more flexible licensing concept than the ridiculous LPL proposed under NPA17b. The CAA are going to have
such fun sorting out how to deal with that, should it ever happen.....