  It is argued that the Next-to-MSSM (NMSSM) is unnatural from the point of
view of cosmology and fine tuning. In particular, such singlet extensions to
the MSSM do not provide a simple solution to the `$\mu$-problem'. Models with
singlets can be constructed using gauged-$R$ symmetry or target space duality.
However their superpotentials have terms in addition to those of the NMSSM.
