I think if PD used some serious focus testing and had community managers and an official community presence, then a lot of the apparent problems would be eventually solved. The UI might be more streamlined, some obvious features (like looking around with the right stick) would be present, the online might be stronger, the game might be not be so impenetrably based on slow progression, etc.
I think the whole "closed off bubble + visionary auteur" thing has worked for them for years, but this is about where it should end and become something resembling a normal development studio.
It just seems like Kaz Yamauchi went, "This is what GT is," and then they closed themselves off from the outside world and went to work on that, and that was that. A lot has changed since then; there's a competitor around that saw that there was room for improvement there. Sure, GT is still a huge brand name, and it's still going to outsell everything, but they can do better. It can retain that GT "feel" that people love so much and yet stop being so clunky.