The part of my post you initially quoted I was referring to those who don't buy Gran Turismo or other realistic games at all, that demographic. I know these people exist, their comments are all around online and I know many in real life. They just don't care for the realistic, "boring" driving that simulators offer and having perfectly realistic physics will not change it.
Then as I say there is the demographic that does buy GT but doesn't care for the specifics of cars/tuning/physics and just wants to race popular sports and supercars in a casual, structured game. Again, I know this demographic exists, how big it is, and how many are turned off by GTS, that of course I don't know.
My real-world experience lines up a lot with what you're saying. A fair amount of friends know I'm into "racing games", and when we talk about it, they tend to prefer the lighter titles like NFS. And yeah, a lot of them tend to consider realistic synonymous with "boring". When I share the story of someone I used to play with going on to win a racing seat with Nissan (Bryan), they think it's very cool, but comment that it'd be a useless feature for them, as they're just not that dedicated to a game. They want something fun, where the feeling of being good at the game comes quickly. GT and FM, even if they're not to the level of realism as things like iRacing, AC, or PCARS, still feel very punishing and unforgiving to those not well-versed in basic car dynamics.
If PD nails that aspect of GTS, and really delivers on this promise of being approachable for all age levels,
without sacrificing realism, they could have a hit on their hands. I think cracking the "realism = boring" issue some people have – whether its justified or not – is huge, possibly even more so than the traditional GT approach of piles of content. The trick is to make the learning engaging: make assists approachable, with clear benefits and drawbacks, and incentivize removing them. SRF was an awful addition during the PS3 era: it didn't teach newcomers about the physics engine the game utilizes, it taught them how to exploit a completely different one.
For some, it's an escape: they just want to drive a few of their favourite cars, either stock or tuned to their desired level. They want to create rides that they would in the real world if it were possible: GT does a reasonable job of that, but it lacks in some of the visual customization aspects compared to other titles. Judging by what we know of GTS so far, its a two-steps-forward, three-steps-back situation: finally, a livery editor, but almost no tuning otherwise.
It also should be noted that, for any number of reasons, the latest NFS seems like it was far from a success, at least critically, and going by how quickly it was heavily discounted. It certainly was a disappointment for me in terms of arcade racers: I found FH2 to cover almost everything it did far better, and on PS4, Driveclub is the better game, even if it's fairly different in execution.