Not sure.
I was there with mrt and everyone wanted to end race.
It changed to LX4 with a different track and they left
Both pretty new combos, but apparently no appealing???
It seems that the users spend less time on BJ than on other servers, which is natural.
It also seems to attract drivers very quickly compared to race2 or race3 once a few are on, so more "volatile" population there. If you do not reach the threshold racers value it remains dead. Find 2-3 mates and spend some minutes there, it could well fill up