The problem with a permanent boardercross course is logistics. The course takes up A LOT of square footage and has the lowest usage of any features in a terrain park setting. We had a full time course at Mammoth for years that was used for USSASSAAASSSSAAAAUSSA (whatever it is now) events. That was one of the least used runs yet had one of the higher maintenance costs of any run on the mountain. The course still has to be perfect for the 10 people a day/week that might actually use it as a BX run.
Boardercross has been a part of the scene for twenty years and saw it's heyday in the late 90s into the early 00s. Since then it has been in a steep decline. The olympics and f-games have done NOTHING to improve the participation in this aspect of snowboarding. As evidenced by the fact that the two things people still bring up about BX are Rippey(backflip) and Lindsey(epic fail.) Nothing notable in the sport since 2006 basically.
Like has been posted before- If you want that feeling then group up with a few buddies and barge your local park run hitting all of the features at speed without slowing down or stopping.