I see what the OP is talking about though. If you look at US-93 without considering topography, it sure does look like a straight-shot shortcut between LV and PHX. Zoom in on the topo, though, and it looks less promising. Plus, it's pure flyover (see what I did there) with no possibility of intermediate traffic other than (??) Kingman AZ. And I strongly suspect that there's more traffic between LV and the LA area (air and interstate freeway) than there is between LV and PHX (air and a 2-lane road). So from a commercial standpoint the LV-LA HSR line stands a much better chance of at least breaking even. Maybe that's why Virgin is still pursuing it?

Still if the hyperloop fanbois want a spot to demo people in a pipe, maybe LV-PHX is a place to do it.