Holy totally missing the point!
With nothing to aim for or look forward to, life gets boring pretty quickly.
Imagine how much more enjoyment someone who had to work months/years to afford their car gets out of it than someone who was born into an incredibly rich family and has everything handed to them on a plate.
It's. Just. A. Game.
Here's what I look forward to: getting married, starting a family, being able to pay off my bills, a promotion, several more pranks from/to my friends, and so forth. Not getting 100% in Super Hyper Sequel Roster Update 2010 Mark IV.
If you are the type of gamer that feels they must unlock and earn everything, that is perfectly fine. However, all gamers are not like you. I have a day job that's 8-10 hours a day. I have friends that want to go out into the real world for drinking, driving fast cars, golf, shooting, pranking, talking with girls, more than talking with girls, and generally being social while not being behind a headset or a controller. This leaves a small amount of time for me to play video games, and, consequently, cuts into my ability to unlock things.
However, you'll note, that I paid the exact same amount of money for the game as you did. I bought the exact same content that you did. Our discs are likely identical at the bit level. I already worked to afford the game - I worked hard and saved my money to hand over for the disc. This is why a game that already has everything unlocked is not like getting an expensive car without working - I already worked to buy the game!
If anything, having things locked without the option to put in a cheat code to unlock them is akin to working for years to buy that shiny new car, paying for it, driving it home, and finding out that until you've spent another $4,000, you can't go any faster than 45. Make the full unlock option be a cheat code, and then color the icon of the save to, say, red instead of blue. If you have a blue save, then you haven't unlocked everything with the code (and have done it through your hard work).