Depends on what distances you are travelling I suppose; the prices for longer travel are, imho, very high and sure it is comfy but compared to a plane? Planes are cheaper and much faster. At the same price I think many would still take the plane. If trains were vastly cheaper, then maybe it would change a lot.

But only inside the Netherlands, I only know a few commuters in my circles who go by train; the rest drive a car, noting inconvenience (train then tram instead of door to door) and, more so, high prices as reason.