I agree that, especially for cars that were ordered when all the park assist features were included, its unfortunate that the features are not operable upon delivery.
However, I still find it rather shocking that so many people can't drive their car without assistance. Folks that live in Europe or super crowded cities with teeny tiny parking spaces where you literally need to squeeze within an inch, I understand parking assist is a huge benefit/loss, and one that is expected and a very important feature. But, normal day to day driving, I'm really surprised so many people can't park.