Flippant comments like "Did you actually read the PDF?" are exactly the kind of needless small escalations that destroys the tenor of commentary at HN. Any time you write that, you could be writing "It's discussed on page XX". If the comment doesn't deserve a cordial response, then just downvote and move along.
He responded to your points about the linked article. You went back to discussing why his language was out of line. Now you're destroying the tenor of commentary. Just append the etiquette suggestion to your previous post.
You can't edit a comment that's more than an hour or so old. Reasonable people can have disagreement about the ground rules for online discussions, and it's helpful to get everyone in the same page in a constructive way.
The weight of a 10' diameter steel tube with 1" wall thickness is 125,000 lbf per 100 feet. Note that does not include the reinforcing braces, that is just the plate. The actual weight could be easily 2-4x greater. It also doesn't include the weight of the solar array.
My bet is that it's not significantly different to compare a light rail (subway-like) system to a hyperloop in terms of weight.
The weight of the track ballast alone is more than that. Gravel is about 100 pounds per cubic foot, and you need about 12 cubic feet of ballast per foot of track, or 127,500 pounds.
Then you get to add the rails and ties (or concrete sleepers), plus the vastly more heavy rolling stock.
The reason I said that the weight of the tube doesn't enter into it is because the tube isn't moving. The only thing that matters in terms of energy use is the rolling stock.
The motor that it carries with it is about 146 horsepower. That's less than a Kawasaki Ninja street bike.
The General Electric E60 locomotives currently in use on Amtrak crank out 6,250 hp (4,660 kW) and weigh 423,000 lb (192,000 kilograms).
The weight of the tube doesn't really enter into it.