A bad interface is a bad interface and going multi-platform isn't the reason for that, it's just used as an excuse. That said, I found Skyrim's UI to be an improvement over Oblivion and most of the issues - like the levelling system - were obviously just bad design and not console related. It didn't get in the way of me enjoying the game.
A bad interface can also be (and often is) created by trying to accommodate two wildly different platforms. Consoles don't have to be the "bad guy" or something silly but quite often there are design concessions made for them that cause issues in the PC version. That's why people get upset about multi-platform releases with regard to previous PC franchises. In the case of Stalker specifically it had all sorts of technical and design problems, I'm not sure adding multi-platform to the mix is going to be helpful. It was a really punishing and complex title, I don't see it doing well with the console audience without being significantly watered down. They couldn't possibly accommodate the user interface requirements on the console without cutting functionality just as an example.
In any case, it will be interesting to see how the successor to Skyrim measures up in this regard, Bethesda has given the PC version all sorts of post-release attention since its sales were supposedly quite good.