I wish they would show me the whole README not force me to click on show in desktop mode. The fact they show that button tells me people've complained about the mobile mode enough, cause without that link I would just set my browser to render as a desktop browser.
I love GitHub but mobile UX is one thing that kills me about the web, and it's not GitHub's fault, lots of websites get it wrong, especially ad riddled sites, or sites that redirect you to their mobile page only to not take you to the original content.
Tried it out ages ago, then opted out of the beta. Now it's back, and there's no way to disable it.
Pretty sure I'll be deleting my GitHub account in very near future. Really over this kind of distraction-oriented crap being forced onto frequent users. :(