Because of all the people who use it to troll; it's now branded with the stereotype of being a trolls car.
I've been in lobbies where the person in the X1 has been the only person not ramming (except the host), but everyone starts whining "kick X1!!! XXPPP". The host decides to keep the hypocrites happy and kicks the RedBull
If I'm quite 'ok' with the host (usually am

), I'll ask them "hey, do you mind if I cruise in my X1", where I'm usually told "yeah sure NP".
This results in the other people not complaining about the X1.
Anyways, enough rambling; sorry

I do believe that if you ask to drive the X1 first, the host/racers realize your not going to start trolling and they accept it.
If you just jump on track with it, and just touch someone you get t'evil eyes.
EDIT: I should point out that it's Free Run lobbies i'm referring to, and if the race is started in said lobby I always change my car. I can't stand people racing those things against anything else.