The problem seems to be: if you could build a partially evacuated tunnel on top of pylons, you could build a light rail system on top of the same pylons with th

The problem seems to be: if you could build a partially evacuated tunnel on top of pylons, you could build a light rail system on top of the same pylons with the same sized cars and it would weight less since the track weighs less than the tube and you could replace the car's 1500kg batters with drive motors and power them off a third rail/over head wire. Of course, this would have rather poor capacity, but that's a problem with the hyperloop as well. It would also be slower at maybe 200 - 250 MPH, lowering capacity further. But if someone claimed they could simply do a 250mph light rail at drastically lower cost, people would necessarily be skeptical. Adding a bunch of really interesting high speed tech on top, shouldn't change that claim much. About the one way I can see it should change the skepticism is if the increased speed increases capacity sufficiently. Which seems not to be the case.