I was always bothered by the ghost issue during the online races.
I'm trying to race clean and fair, not just for pleasure but for the other drivers as well. From time to time IT ALWAYS HAPPENS, an idi%%$/ came, and starts to bumping his car to all of us. And that REALLY piss me off. I drive on saturdays with my father-in-law and some regular friends, we have full damage and tyre degradation, so if some guy come and start to mess around, it gets tricky. Luckily, most of the time those guys just stay for 5 seconds because of the damage, but it's annoying.
Recently, I find out we could really bump our cars into each other, but just by accident. And I thought it was because I set the type of race in competitive. It's really fun, and because we always race with 5 or more laps, the races became glorious sometimes...
So, this option is helpful to some guys. Not for me but is a great thing to have I think.