Sure, I'll reduce it to "Unless people make an advancement in structural materials similar to the invention of steel itself, which is to say 'fundamentally world-changing,' hyperloop is nothing more than an inspirational pipe dream, similar to world peace." (EDIT: This comment may actually get called out in the future once Hyperloop is fully deployed, as an example of some idiot's words. So it's probably more than a little dumb of me to have said this. In my defense, it's based on Hyperloop Alpha, as it's presented in the whitepaper. Their design could change radically before deployment.)
If you're planning on building a closed loop out of steel, and there's nowhere for the steel to go when it expands in summer, the plan may need some rethinking.
The best I can think of is some kind of inner lining, so that it has a segmented hull, like a caterpillar: https://www.google.com/search?q=caterpillar&tbm=isch
But it would need to be very strong lining in order to prevent any leaks between the segments. And any kind of a leak would need to be detectable and would shut down the hyperloop until it's resolved.
Between the wildly optimistic cost projections and the fundamental engineering difficulties, I'm much more inclined to call it a pipe dream than a perhaps-future-possibility.