yup your right. and so does N sibanyuensis(sp?) if given the chance. i have 3 neps in 3 different mediums! one is in Bark, coir fiber, and some peat, another is in straight LFSM and the last is in a mix of peat, vermiculite, and perilite. the last one have a bunch of peat in it. they all grow fine in their own mixes.Atleast one plant (N. argentii? Don't quote me lol) auctually grows it's tendrils into the soil I believe.
Nepenthes tentaculata is also found growing in pure, live sphagnum moss.