I have two thoughts and opinions on the shift-s topic. They are different depending on the type of race you are in.
First, during the week, I like quick and short 5 lappers. I log on for maybe 2 hours and the 5 lappers allow me to quickly be racing and have many of them in the short time I have. In this situation, I feel that shift-S is a must if you have a bad wreck. You're not going to limp back to the pits, fix the car, and get back out to battle and have a good finish. Why ruin it for someone coming up fast as you are spun out and/or badly damaged when there's going to be another race in 5 more minutes?
The second situation is, of course, longer races, organized, and league racing. I don't like to see folks shift-S in these races as they are not just quick-get-going-and-have-a-bit-of-fun racing. This is where the realism comes in. Wrecks and spun cars are a part of racing. If I spin in a long/league race, I'll either just sit tight if the cars are close together so I don't surprise anyone with my moves, or if close to the side, back up to get a bit out of the way until it is clear for me to recover. Especially in league racing where it tends to be an hour or more long.
In NAL at AS Historic reverse, I was wrecked and very badly damaged. Of course, I did not want to just quit as it was a league race, and of course as luck would have it, it was right at pit exit! I ended up limping around the track, very badly damaged and very difficult to control. As I saw the pack coming to lap me, I pulled off and continued on my way in the grass well away from the race. Eventually I made it back to the pits losing I think 3 laps to the field. But, I didn't quit, it was league. Had to finish, even if it was a terrible finish.
Was reset mentioned here? As for reset, I don't think it should even be an option. Nothing is worse than obeying the yellow, seeing a car spun, cautiously avoiding it, just to have him reset right on top of you. NEVER EVER reset when you spin when involved in a race. At least if you make the mistake of trying to recover when you should just sit tight, other's can get warning of it by possibly seeing and interpreting your intentions. But reset is just instantaneous and there is no warning to other racers coming up behind.