It's so interesting to see this posted here. Had a chat with a few GTP members just yesterday about the same thing: with GTS moving in such a drastically different direction, it's the optimal time for T10 to align Forza (Motorsport) as the replacement for old GT's. Unless PD is sandbagging by holding all the old GT6 Premiums back for the next full installment, there's no way any other franchise is going to catch Forza's count this generation, and it does one better than GT6 by having such a broad list of cars and disciplines.
I know some people are tired of it, but GT's car-based quasi-RPG approach is what I loved about the PS1, and to a lesser extent the PS2, generations. It felt exciting having to bargain hunt for my first car, and carefully budget for the gradual improvements it saw. The later games threw that aside. I love that the only thing stopping me from entering a race in the PS1 days was my license level, and it was up to me to find a competitive car. GT6's career feels so linear by comparison, funnelling us through races with specific cars.
For those that want access to all cars off the bat, Forza already nails the perfect middle ground IMO: everything's available in Arcade Mode, but if you want to tune or customize, you'll have to earn it. And it won't be the utter grind-fest that GT became on the PS3. Even that wasn't a huge concern in the older games: I didn't mind running Red Rock over and over again to sell off the Speed 12 and gain 550k, since no car cost over 2 million. Now, GT has 20 million credit cars, but race rewards haven't kept pace with that inflation.
Forza gets so much right with the old GT formula, but there's still a few things I miss. I realize it's probably never coming back, but the online Auction House could easily stand in as a Used Car dealership. T10 could populate it with some cheap used cars prior to release, and then let the community do the rest. Maybe even keep some of the T10-provided stuff in permanent stock, to ensure nobody is left without a decent starter. It can't be too hard, right?
I think the most detrimental thing to GT has been the change in attitude about the franchise itself. Where as the earlier games were about the love of cars, and the joys of "regular" models, the later games have become increasingly about what relationships PD can boast about. Sure, it helps Polyphony become more recognized in the automotive sector in real life, but at what cost to the games? There's nothing accessible about a relationship with Bugatti, or the Vision GT project. Forza still has a reputation as a supercar-heavy title, when it's arguably GT that's focused more on those (excluding Standards, as they're carryover content). GT Sport will only reinforce that, since it's primarily PD-designed fantasy race cars and VGT's.
I'm very curious what FM7 will turn into, as it will essentially have that particular part of the genre all to itself in 2017.
