My point, not well made, is that you can fly a published NDB procedure using a GPS.
Yes, if it is IFR En Route and Terminal or better (i.e. including Approach) as per AIM 1-1-19, then you would be daft not to use it instead of a horrible ADF.
If it is VFR panel mount or hand held, it is a great addition to situational awareness while flying the needle as a primary indication.
What struck me in your comment was your point that the NDB approach can be flown within tolerance (with the error on the wrong side) and still hit terrain. Is the Shoreham NDB approach procedure ill-conceived ?
The other is to fly some form of abbreviated procedure, whereby one just intercepts the inbound track like it was a localiser.
I know at least a couple of places where that would be a really bad idea, for precisely the reasons you mentioned.
...apart from having an panel mounted approved GPS IFR installation. They would only do that if your flight plan indicates /G.