The difficulty is scalable, so I really don't understand why people are saying it's not a challenge. You can make the game as challenging or as less challenging as you want.
It's not really about it not being a challenge, it's simply now the way games are seen, marketed, and even sold are skewed tenfold. In the good ol' 80's and 90's (Yes, I'm going there) everything was simply about the game and the game alone; nothing about achievements, gamerscore, or how many online buddies you had...amongst tens of other things. If the options were even there you would have unlock them - remember playing through certain games where you either had to die in a set amount of times, or simply unlock an easier, lesser difficulty? The same thing applies now but instead of having to at the very least "earn" your two crutches, they're given to you right from the get-go. I wouldn't say it diminishes any factor of the game as a whole, but if it doesn't at least make you raise your upper lip, if even for a second than games really have become a great deal easier than they should be.
Yes, I went a bit further in the opinion I was aiming to get across, but it's still the same - fundamentally. All in all, it seems that everything about the game is about anything else but the game itself. More than one opinion, or even a based fact is here but games have lost endurance, difficulty and even replay value to an extent. Unless games now have a possible 100,000 (exaggeration) possible outcomes and each of those outcomes have 100,000 possible, completely different endings playing through any game now just to get any last nickel worth in achievements or trophies doesn't make the game longer. Playing through a newer difficulty doesn't make the game longer. The same can be said for starting with a new car, going through with the intention of getting gold on every license test and the provision of shattering every known lap record doesn't make the game longer, it only prolongs an experience that, for the sake of truth has already ended.
In all, appealing to a younger, more casual audience just to increase your sales or simply just to gain a a larger bode of familiarity is perfectly acceptable especially as many have provided he or she might love cars but might be timid to pick up a controller and play a simulation racer is fine. Dumbing down the game as a result of that, even if it can be disabled and you not being "forced" to use it is a bit of a put off.