Yes, physics comes first but detail on tracks is important too. If it lacks in detail it doesn't look or feel like a real track. It's not that important when actually driving but in case with this GPL version it's just too plain nowadays. In real life it's a track where every corner is different but in this GPL version many of them at least looks the same, because there is no extra detail which would remind you about the braking points etc. Of course I don't agree when the fancy detail on tracks goes ahead of the accuracy or physics.
Btw detail on tracks also affects the feel of speed. The more stuff goes by your monitor, the faster it feels.