He's a geeky sort of chap himself (see picture) and apparently very much likes his geekster fans, rather as Neil Gaiman does. I think his sympathies lie with anyone who's authentically themselves. Thus he twits Magrat via his writing when she's doing something silly she thinks she ought to be doing because she read it somewhere or someone told her to do it that way, but not when she's doing something for her own reasons. (I hope that made sense ... .)