A standard argument against representational painting in the modern age is that it has been superseded by photography. This argument is so intuitively appealing that we tend not to consider its conceptual basis.
The argument rests on two implicit assumptions:
1. Representational painting is not a goal. Improved representation is the goal.
2. All technological progress toward a given goal constitutes improvement over previous technologies.
Let's not tackle these assumptions in terms of the desirability of technological progress per se. Rather, let's consider a simple human fact which we all know: sometimes you work very hard for something, but once you get it, you find you don't like it very much.
I believe that this has happened, at least for some people, with photography. Photography actively resists some of the merits we have come to depend upon from representational painting: profundity of observation (the ease of photography promotes facile observation, emphasizing superficial formal qualities), a sense of life which richly imbues the image (the mechanical nature of photography is poor at evoking the vitality of all things and places), density of concept (a photographer without a full production crew has difficulty staging a scene in order to layer conceptual implications into the composition itself), intentionality and meaningfulness of the work (photography has a strong bias toward noticing happenstance, rather than creation from an internal wellspring). Photography has many virtues, but they are not the same virtues as painting.
Representational painters are accustomed to cringing and special pleading when the fact of photography is triumphantly waved in their faces. I think they should set aside their defensiveness and forthrightly say, "Before the photograph, we thought we wanted simply to make the most physically accurate representation possible. Photography taught us that we were wrong. The painting technology which we thought of as an intermediate measure turned out to be the best measure for many of the qualities we sought. So we are going to acknowledge that once we accomplished our old goals, we didn't like them very much. We are going to change our understanding of what we want. We are going to go on painting."
This is legitimate.