I agree. However, would you say that other modern racers look cartoony/unreal? The argument isn't that PD has gotten worse, but that everyone else has gotten better.
The comparison was made that other games don't look real and only PD can make a realistic racer. With the latest hardware, other devs can also make realistic racers. I bet when GT7 comes out, one could put together an assortment of screenshots/clips from different driving games and no-one would be able to tell by looking which sample was from which game.