Its simple fun with attitude and cheesy rock music! Good old non tarnished sega goodness of yesteryear!
Seriously, the closest comparison I can make is to say, burnout. That may not be a good comparison, but i get a kick going from a->b and looking for ramps, drift opportunities, parking decks to drive off of into traffic, etc. If all you're doing is reaching your destination and getting minimum fare then yeah I could see it being dull.
edit: and I spend a minimum of two hours with any game bought. Just a rule to live by.