I would guess because the world doesn't revolve around you? You can download the full installers and bring them over on a USB, it's a trivial operation. You can

I would guess because the world doesn't revolve around you? You can download the full installers and bring them over on a USB, it's a trivial operation. You can also build on a networked computer and then bring over the final file(s) to your air-gapped system.