The 2012 version was only very hated because of it's name. The gameplay was some of the best in the series, and the multiplayer offering is by far best of the series as well. Also the most well-designed open world in Need for Speed. Really sells the feeling of being in an urban labyrinth.
Stories in racing games is an outdated concept, and should remain a thing of the past. Only game that's really done it well was Driver: San Francisco.
It was hated because it turned Need for Speed into Burnout. Even people who love both NFS and Burnout didn't want the two to mix. They should be their own thing. The open world was absolutely atrocious, a mix of brown, brown and more brown. It was empty and bland.
They tried to blend NFS and Burnout. What we got was a either a half-assed Burnout, or a shit NFS. Take your pick.
NFS was a series before Underground. A great series. It was about getting the chance to test exotic cars you could never even touch on some of the most fantastic roads on the planet (fantasy roads, but still). It had this car magazine culture all over it.
Of course, when an exotic handles like a go kart, the whole exclusive feeling goes right out the window. THAT is what Most Wanted did wrong.
I continue to see Driveclub as the thing that actually comes closest to the older games. EA should look at that game, and their own past before Underground and actually look at what made the series succesful to begin with.