And none of their plots are worth mentioning. They are send-ups and parodies, and in the case of Xanth, not particularly intelligent or amusing. Pratchett is the only one that can be taken seriously, but that's for the points he is making, most of which are pretty rudimentary and not particularly insightful. So really, your examples really seem to be saying that you can't, in fact, write fantasy without violence, unless it's a gimmick.