Yes, Crappy automotive SW is solely because most if not all infotainment SW is written by third party vendors. GM/Ford/FCA have engineers who are good at drafting Requirements and throw these said requirements over the wall to vendors like panasonic, bosch, Lear etc. They write 100 page documents on how the system needs to behave and these OEM vendors need to deliver these infotainment black boxes without any significant issues. (You can imagine why, if the infotainment board (Say intel or Qualcomm FW) has a bug that was found in production; they would need to update over USB or some other form debug method and reflash on the side of the production line and this cost hundreds of millions).

Again tesla has done a great job and implemented OTA and some of the automotive companies are following suit but this still does not help them much as the updates are given by the vendors whose sole job is to cover themselves (So most updates will go through a year of testing even for minor changes to make sure not to brick anything)