It just seems to be that nearly everything that is said about GT6 is leading to complaints.
Alright, yes, so we may not see the new sounds by the time the game is fully released, but take it this way. The core of the game so that it functions, works, and can actually be playable, can take much more time than one would imagine. PD had to work on a console which many developers claimed, was difficult to develop for, and as a result, there were several games that took longer to be ready for release due to that downside, and in some cases, several games didn't reach the potential they possibly could've. Considering that Gran Turismo 5 was PD's first full-fledged (non-Prologue) title on the system, I didn't expect it to be a nail out of the park.
Many also forget that PD is quite a small team, MUCH smaller than other developers around the same level as PD are. The less people means that the more time a game may take, because it won't be able to rely on as many people to work out with the game to make it better, faster.
Lastly, I'm sure there have been several ideas that PD has been talking around with during the years of development that GT6 was in, which ofcourse AGAIN, can take some time up. It's not like they suddenly know everything they are going to do on the first day, some of the ideas likely come over time.
So, Console that's hard to develop with, Small team, Ideas and Developments that may have been scrapped over time, it really can add up alot of time. If there has to be an update for the sounds, so be it, what should matter is that they actually try to get it out for people, whilst they are working their asses off, making sure that the game is in a playable and acceptable form by the release date. Plus, the games will have to be prepared for being made onto the discs soon, since they need to be made well before they are even ready for the customer. During that time, they can easily get more time to work on the smaller features, to make (hopefully) a good amount of you, happy.
So this is why you don't see me complain about Gran Turismo 6.