Personally, I don't _want_ a grammar of graphics; I want a grammar of data, where the data happens to have a graphical representation. I don't want to spend ages piecing together a fancy plot; I want to spend just a little time annotating my data to declare what it means, and then no matter how I slice and dice my data it will show up in a meaningful way. That way I can explore it to really understand it, which is the point of HoloViews (http://holoviews.org). But people approach plotting in lots of different ways, and some people actually _do_ want to spend their time making plots, so they are welcome to their ggplot2!