Most people can't afford them. For the price of one, you could buy a decent E36 race car with enough money left over a seasons worth of track time and a half dozen days with a qualified driving coach. Depending on their rates.
I don't disagree with any of this. Especially in the beginning. As I stated in my post, there are a lot of advantages to sims. There's much to be said for showing up at a track you've never been to before and already knowing the line. But as your experience progresses and the more laps you do on a particular track, the smaller the returns you'll gain from a simulator. At least let's say, a commercial level product that's really designed more for entertainment.
I'll give you a specific example. The Downhill at Lime Rock.
The key to Turn 7 is a slightly late apex and then clipping that apex with your right tires, just kissing the curb and then letting the car just naturally track out. Hit it just right and there's a significant amount of compression and camber through that slot that you can't easily see from inside the car. Even walking the track you have to look carefully, just because of the angle of the hill and corner. You kind of have to get down on your knees and look at it from the right angle to see it. But hit it just right, very precisely, and that compression allows you to take that corner quicker and with more grip & composure than you otherwise could. When you drive the track, this becomes readily apparent (when you get it right). If you hit that mark, repeatedly, you'll naturally start to pick up speed, getting into the throttle earlier and harder. But it demands precision. Get it wrong, even just a foot off at the same speed and you'll likely have a very white knuckle moment as you get spit out onto the grass at track out on the main straight. A lot of people who do end up into the wall on the opposite side.
Even what I consider to be the best commercial simulator out there, iRacing, doesn't quite get this compression and the affects it has on grip and composure, quite right. To be fair, the relationship between grip and track camber and compression, along with suspension movement and slip angle, is highly complex. And it results in a LOT of 0 & 1 floating back and forth in real time.
This is just one example, out of dozens that I could think of, and it's why I say that commercial grade simulators are a great and important tool to learning a track. But if you're really using it to narrow down your lines and whittle away 10ths, you better be using something that's as accurate as possible. Something like Project Cars is a very effective took for learning the layout. More than that, not from where I'm sitting. It does an even worse job with the effects of loading and unloading and at tracks like WGI where half the corners on the track are all about compression and camber, so you can see where it's leading from my perspective.
All that said, yes, if I'm heading to a track, I always try and spend a little time in my rig first, just to freshen up. And I think it helps.