I think that story is confusing two different projects. The "Party train" referenced above only has permission as far as Barstow, where the tracks mingle with those of the BNSF, and it's BNSF that carry on to Victorville. The "other" project, the high speed route, is the one that starts in Victorville.
In both cases the problem is getting the capacity "down the hill" to San Berdoo. In reality the capacity exists: it's just that nobody wants to give it up even for one paltry train extra each way per day.
Mind you, for $99 each way - even including a meal - it's something even I would only take for a joyride once. It can cost me roundly that same price for gas there and back for an entire family. Greyhound is under $50 each way per person from Victorville.