Among other things, Lev Manovich discusses the role and purpose of data visualization, and data art. For him, the current challenge of data art is not the visualization of impersonal data into something meaningful and aesthetic (as this is already done), rather the challenge is how to data art can help creating a "personal subjective experience of a person living in a data society". I think this is a good point: many visualization tools allow for quick and good-looking visualizations. Maybe even because data visualization is more ubiquitous than it used to be, a work of data art should really appeal or connect to the viewer: make them think, reflect - have a subjective experience.