I have moss that more or less covers a damp shady corner area where I have mainly foxglove, bleeding hearts (Dicentra), ferns and Brunnera planted and all of those plants seem perfectly happy (the foxglove self-sows like crazy); hosta also grew there until the deer ate it all. I did try to eliminate the moss for a while, but, as kniphofia said, it turned out to be a waste of time and effort.