I've never been a big fan of racing, but I do enjoy driving gameplay. Believe it or not, play-driving does not necessarily mean racing.
Track racing is fun once through, but there are so few dynamics. The setting and challenge are exactly the same every time. The player has few options, so the emphasis is on performance of a strict routine. Such gameplay has poor longevity.
I've played a number of racing games, since my best friend is a vehicle fanatic. But only two have seemed open and dynamic enough to coax me into buying them: Need For Speed: Most Wanted and FUEL. I enjoyed the former more, and traded both in.
The beauty of NFS: MW is three-fold. First, there's an open city with a variety of challenges (sharp curves, barriers, etc), shortcuts, and road types for exploration. Second, setting the game in a city with dynamic traffic adds dynamics to races and exploration alike. And third, the cop chase gameplay adds a dynamic, open-world challenge that doesn't distract from the core driving gameplay (as Full Auto-style weapons and Wheelman-style stunts can do).
FUEL really shines when you're dodging trees and jumping obstacles at high speed in a motorbike over varying terrain. It's a thrill I haven't found anywhere else. But, vast as its world is, FUEL becomes redundant quickly and offers poor competition. Varying, meaningful weather was a great promise, but a failed one.
Anyway, judging by the sparsity of such games, publishers seem to believe that gamers who don't like track racing don't appreciate realistic vehicles and vehicle physics. That's not the case. Just because we don't like marathons and drag straightaways doesn't mean we want cars with guns or cartoon go-karts (though I've got nothing against that either). Cars ≠ racing.
Many more people are interested in driving gameplay than are interested in NASCAR, Grand Prix, drift racing, drag racing, and so on. Make a driving game with good physics, a wide variety of vehicles, truly personal (rather than achievement-style) customizations, an open and dynamic world, and a variety of challenge types... and that's a game with broad appeal.