GTP members and overall hardcore audience are unbelievably small part of the GT series consumers.
It would be great if many people here would jump off from their high elitist horse and understood how their opinion clearly matters - and it is very often taken into account by PD - but it is not detrimental, foundational nor exclusive for idea of GT series design, execution, content planning of feature implementation.
Also, if I was in charge of collecting "focus group" data from GTP, I would probably already be in the asylum. Imagine why.
Success of GT series lays in acceptability to casual players. Without them, there is no commercial success.
Imagine just for a second how MAYBE that sensitive line of "acceptability" has been crossed with GT5 being made too hardcore for the casual players. And now that is reflecting on GT6 sales. Because GT5 was too vast, too hardcore and too complex and casual players felt it is not "their" game anymore. So they decided not to buy GT6. Because there are simply no 10 million hardcore players outthere.
So, what are "we" exactly doing with our constant push for GT to become more hardcore, more like iRacing, Raceroom, rFactor or Assetto Corsa? What are we doing for the actual commercial success of the GT series? What are WE doing for its sales in the long term perspective?
I am not sure I actually like the answer to my own question.
I have to disagree with your premise that GT5 was too hardcore and complex for the casual gamer. Except for the addition of the online mode, what exactly made the game more complex than, say, GT4? And
that game is still named by many as the best game in the series. The problem with GT5 was, in my opinion, that the UI was so slow, and the career-mode was not up to what people were used to from GT4. Online mode wasn't exactly stable, but we had learned to live with many of its quirks over the time we were playing it.
With GT6, PD addressed some of GT5's biggest problems, and they did well in that regard. The quicker UI alone is a joy after what you were used to in GT5. But the fact that the new game to this day does not even offer lots of functionality that was available in GT5, let alone an allegedly completely rewritten and improved online code, which might have been improved feature-wise, but proved to sometimes be incredibly unstable, doesn't serve to boost people's opinion about the GT-series and where it's going.
If you're looking as to why GT6 is not as successful as GT5, look no further than exactly those casual gamers you mentioned, who were bound to be much more interested in the PS4 coming out at the same time than a racing game being released on a dying platform which had already proved to be incapable of dealing with all it was supposed to do in GT5. Why would those casual gamers have bought a very similar game on the PS3 one more time? Combined with the fact, that the time for the release window for a PS3-game was running out and the game
had to be released when it was, i.e. in an incomplete state, it's more us hardcore-fans of the series who haven't got any comparable game on the PS4 that would entice us to switch just yet, who were buying the game, and therefore are disappointed by what we have (not) been presented so far.
Of course, all of us, casual or hardcore, only pay more or less the same amount of money for the game, but I think it's exactly the people who play the game for hours and hours, who get annoyed enough by some bugs or quirks to actually voice their frustration and post them on a forum like this. The fact that only a tiny percentage of all players frequent these pages doesn't mean that they don't represent what many casual players thought about the game when they were playing it. So, of course, the feedback is overwhelmingly from hardcore players, but the majority of it is not incompatible to casual gamers' needs.
So, if you're asking what we do for the commercial success of the series, I say we offer our collective "expertise" as to what we think ought to be changed for a future release to be a better game. That doesn't make us entitled to anything and we do it for free. But I think it would be extremely foolish to completely disregard what the people playing the game the most (and I'm sure that even includes PD employees) think about the game.
I'm not saying PD is incapable of delivering a great game anymore. I also think, given enough time to properly implement and test all features, they will do so on the PS4, but it will need their undivided attention, which is something they haven't had in a long time.