Well, literally every other application on my tablet utilizes the available space. There could be a collapsible feed view on the left and a collapsible community sidebar view on the right. When I hit reply button, it could open up the comment editor on either side. Or maybe I could pin the post on the left and scroll the comments on the right (or vice-versa). The arbitrary width limit is also forcing images to be smaller than they need to be. And clicking on the images.will just show them in the size they already could have been shown online if the view was fitted to the screen width.

At the end of the day, I paid for a device with a large screen because it can comfortably display more content. The device and the OS support landscape orientation, and technically so does Liftoff. But if the developer feels strongly that users should stick to portrait mode, then they can simply disable landscape mode altogether so it doesn't redraw itself when I physically rotate the device from one to the other. Otherwise, they should have options to use the extra screen width in landscape mode.