Racing and even speeding on the street is bad, M'kay?
It's one thing to risk your ride and yourself, but it's an entirely different--and far far worse--thing to risk the lives and property of others on the street as well.
Say you're pushing hard down a twisty road and go around a blind corner. Some mother and two kids are stalled out in her Minivan not more than 40 feet in front of you before you see them.
How could you live with yourself if you take them out in an 80 mph crash? Take it to the track. Don't wipe out some innocent people with your foolishness.
To an imperial city, nothing is inconsistent which is expedient.
--Thucydides, 420 BC