The mobile experience is a single page app. It's not very good.
Agreed. I don't see the use case for Reddit to be a SPA. Given that it's a list of documents linked together, I can't see a better use case for a plain old static hypertext document.
If you land on the desktop site, it consistently pushes you to download the app, and buries the mobile link.
It is an incredibly ham-handed way to try to push people into the app. Extremely irritating.
The mobile site seems to already be a SPA. Clicking on comments or the next page button shows a loading image, while the top header sticks around.