However, while you personally might not see the point of this feature, it's worth keeping in mind that it's intended to help players of all ages and skill levels enjoy the experience - and nothing sums up this commendable approach than the following Reddit post by MyAudioDNA:
I have 3 kids ages 7, 4 and 3. The 7 year old is capable of playing the game normally and the 3 year can't really play, but likes to hold the controller and push the buttons. However, my 4 year old had a stroke just after she was born and her right side is not coordinated enough to hold the controller in a way that really allows her to play with us. Well, thanks to Mario Kart's new Auto Drive feature, she can now steer with her left hand and let the game drive for her or vice versa. I'm sure this feature will be an annoyance to many, but for my daughter, who would otherwise not really be able to participate, it is the best feature ever added to a Mario Kart game. She is currently sitting in my living with my other 2 kids and my wife and all of them are playing Mario Kart and laughing their heads off. This is truly a day I won't forget thanks to Nintendo.
TL;DR: My daughter had a stroke just after she was born, but thanks to the Auto Drive/Steer features she is able to play with me and the rest of my family. Thanks Nintendo!
Irrespective of how you feel about Nintendo's attempts to make its games as inclusive as possible, that's one incredibly heart-warming story.
Thanks to Kalmaro for the tip!