Generally agree with your view, but Highland Model 3 has actually 17 instead of 14 speakers.
It´s beyond me how they are adding 21% speakers to a sound system I have not really heard any general criticism of while dropping 100% USS.
I think it is one of those things where a single person at the top making decisions alone is not a good idea. Everyone makes mistakes, but in a team decision it is unlikely all make the same mistake at the same time. On the other hand, without many of Elon´s decision that a team likely would not have dared to make, Tesla wouldn´t be where it is now.