It's probably due to the lack of popularity with manual gearboxes, lightweight sports-cars and circuit racing in general?
That might change in the next few years now that the Americans have bought Formula One. If they can go to town on that like they do for oval racing and some of their other sports, it's going to be great, and might spark a fresh interest in circuit racing. Particularly if Haas F1 start slowly climbing up the ranks.
It's interesting he went straight to drifting in the game, I guess that is popular there. I also think it shouldn't be sniffed at (it hasn't) and should be catered for (it has to some extent).
If LFS is about simulating all manner of different cars, then it should naturally follow that it would simulate well all the different things people do with them for fun.
One of the things I love about LFS is how it's quite a sandbox game, rather than a Formula 1 simulator that you can only do set Formula 1 things in. Or a Rally game, where you can only do rally things. Or some kind of autocross/drifting game that feels awful because the developers have gone straight into trying to approximate how drifting feels, without it being an emergent feature of some reasonably solid physics/tyre engine underneath.
Whether you're circuit racing, oval racing, drag racing, autotesting, drifting, rallying or having a car chase around an open config, we're all essentially doing nothing but having fun with cars, and learning/refining skills at the same time.
Making a more accurate physics model, adding more cars, more tracks, simulating more conditions etc, adds to and upgrades all these different ways of enjoying cars for everyone, no matter what they bought the game for. That LFS can handle drifting so well, despite not having it designed in, is a testament to how well it has been made. Same goes for driving on two wheels etc.
Maybe once S3 is more mature, there should be a new trailer made that emphasises that the game really is a sandbox that isn't just hard-coded to simulating one narrow way of driving and enjoying cars.
I'd love to see a Race of Champions style track in there for example.
Embracing it as a drifting game as much as it is a racing one would be a good thing to gain interest in new areas that perhaps the game hasn't sold well yet. It takes absolutely nothing away from the racing side of the game. If anything, it shows how dynamic and consistent a world it is you get to drive and race in.