>I'd also say from the UX perspective there's a bit of an expectation that [ left side in a list right side in expanded view ] tends to denote a relationship between the two when in fact there is none.

I agree. I clicked the links on the left expecting some sort of in-page action, but was met with tabs being opened which is counter-intuitive to what one has come to expect with in-site/in-app menus.

Or perhaps I've just been spoiled by UI's like that of Alien Blue for Reddit?