Automatically going into park when you open the door is a smart safety feature. The number of people who forget to put their car in park is surprising (I've been guilty of it from time-to-time. The need to be able to have the car into Drive (or Reverse) with the door open is VERY minimal and is easily effectuated by putting the car into Drive from Park once the door has been opened.
Complaining about the radio volume dropping when you open the door falls firmly in the #firstworldproblem category.