I'm sure this might have been asked already but I couldn't find anything.
Especially on long races players tend to leave when they get wrecked early on.
A huge fun factor for me is having to dodge wrecks but many players are not willing to watch for ten laps. So as an example, you start with 24 players, 14 get wrecked but only 4 of them stay on the server. 5 laps left, 10 alive players still on track but only 4 wrecks. It can get a little dull, most notably on ovals and fig8.
I believe there must be some technical difficulties with having the cars stay on track?! Otherwise it would have been implemented right? Because I don't think I was the first with that idea.