This doesn't work for an electric aircraft, or many normal public transport methods as they are all focused on batching people up into large groups (planes, trains, etc).
Also, Elon has called Hyperloop 'another type of transport', i.e. nothing like we already use, whereas I would say this idea is just an aircraft with a new type of launch system; not as different as Elon suggests it will be.
However I agree that getting the land to build a tunnel on the surface (or a track of any sort) would cost a lot of money, and tunnels below the surface would be too costly as well.
Although I think lots of people are converging on the idea, sound waves, evacuated tunnels, all that sort of stuff, I think everyone so far has missed the big detail or breakthrough that makes it feasible, after all, these techniques have been known for a long time, just not been taken advantage of because they aren't practical.