i know it will never happen here, but lets hypothetically say we were starting from a clean slate
The reason it's not gonna work is not because of "big oil" or existing infrastructure, or yet another global conspiracy. It's a simple matter of cost, efficiency, maintenance, and ease of operation.
This horse has been beaten to death a million times by transportation enthusiasts, experts and "experts". You can't have a public transportation inside a tube that has to be pressurized and de-pressurized on every stop. And you can't have public transportation that only works in express-mode(that's what we have planes for).
Sorry for sarcasm and OT, but only in America you guys think of new and revolutionary ways to improve public transportation, when your existing systems are barely used and at all-time low.
I spent some time stateside(many-many moons ago), and I remember 'till this day how I took my first bus ride... I was going to work and at the time I had no ride and my bicycle was broken. Walking takes about 40mins, but I figured - whattahell, let's try that yankee bus for a change. Looked up schedule on the internet. A bus goes nearby once an hour, the next one is in 20 min. Gotta take 2 transfers on the way with a huge detour on the final stage. According to website it should take around 50min, so just a tad over an hour to get from point A to point B. It was slower than walking, but I took a chance since I still had enough time and really didn't feel like walking...
So, 2 hours later I finally made it to work, because the first bus was 15 minutes late, and I missed both of my transfers.
One of my co-workers used to take a bus to lightrail to another bus every day... Which was even worse... She used to get up at 5AM in order to make it to work by 8:30-ish.
So called Hyperloop is a novelty toy. It's only feasible as a small-scale publicity project, kinda like that AirTrain at JFK, only less useful.