his comment actually made me a bit sad. in a way he's suggesting that because we've developed photo technology, what's the point in practicing antiquated crafts such as painting? to compare it to a different subject matter - i love typography and modern computer fonts...but i also wholly appreciate (and hope to learn!) hand calligraphy. just because something can be captured or completed in a more timely and efficient manner doesn't make other forms of creation less valuable.
and funnily enough, though the term "photorealism" references a comparison to photos, essentially it's just painting. painting the way it used to be: back before artists were celebrated for their interpretation of the world, attempts to depict it were straightforward and anything that didn't mirror it closely was considered blasphemous. and so it seems humourous to me that if a painter uses this traditional style, some will view it as pointless. when in fact it did us just fine for centuries...and centuries...and centuries.
and just one last thing i swear! i don't think photorealists necessarily render their artwork based on photos...but rather the final result simply looks like one.
p.s. check out one of my favourite photorealist painters, as well as one of the most well known photorealists.
p.p.s. this might also give you some idea of the sheer skill this type of painting requires.