Oscar Goodman is a pompous @$$, but he is right about the necessity of alleviating traffic along I-15. The problem is, this project won't contribute to that until such time that the entire $9 billion, 269 mile route is complete to Anaheim/LA. Until then, it's merely a tourist shuttle from some remote casinos to the main concentration of casinos here in Las Vegas. If people have traveled 229 miles along I-15 to get to Primm, they might as well continue another 40 to get to Vegas.
That's another reason for pursuing the Pittsburgh or Baltimore/D.C. projects: future service to population centers along the route. Pittsburgh, for instance, is envisioned to eventually expand 300 miles across Pennsylvania to Philadelphia. Along the route, it would gain ridership by providing service to other smaller cities: Greensburg, Johnstown, Harrisburg, Hershey, etc etc. perhaps.
What smaller cities exist between Anaheim and Las Vegas? Not much after you escape the Greater LA area, just a whole lotta nothing. And a couple casinos on the CA/NV border.