I know you're closer to 5 than you are to being a father yourself, so you maybe you don't quite understand the benefits to having a game that a father and young son can both play and both get something from it. Just because easy is easy doesn't make it not "brilliant". Many brilliant games have a super-dumb-easy mode.
Breaking is the #2 most important thing in a racing game after accelerating...i wouldn't call the game breaking for you "a benefit"...then again, for a 5 year old...it's a whole different story.