Has Nielsen completely missed the point of Responsive Web Design? Yep.
A mobile what?
Jakob initially makes a sturdy point, an interface specifically tailored towards a specific environment or set of attributes is theoretically going serve the users purpose more than a general, unspecific interface. The actual reality hits once you try and define what the word "mobile" means.
Are we talking about a mobile phone? Is it the ability to make calls what makes a mobile use case? Probably not.The iPod touch already demonstrates how different an iPhone would be if you removed the Phone application. Not very.
As Kyle Beans excellent russian doll project demonstrated, the definition of "mobile phone" has changed so many times in the past 20 years. I'm sure it's bound to change even more in the next 20.
So what makes a mobile a mobile? No one really knows. They could have small screen, or they could not be. They could have a touch screen, or they could not be. They could be on a slow network connection, or they could not be. They could be using a colour display, or they could not be. The rise of "mobile" devices has made it really obvious how broad and varied the web is. All our assumptions get thrown out the (1024 x 768) window.
That's where Responsive Web Design excels.
Responsive Web Design: Embracing Flexibility
The control which designers know in the print medium, and often desire in the web medium, is simply a function of the limitation of the printed page. We should embrace the fact that the web doesn’t have the same constraints, and design for this flexibility. But first, we must “accept the ebb and flow of things.”John Allsopp, “A Dao of Web Design”
That's the opening paragraph of Ethans article. The whole philosophy is built around designing systems that respond to changing environments. We should embrace all the differences on the web, some of those differences may fall under the banner of "mobile" and some may not.
I like to think of a static mobile design a storyboard or keyframe. The full or desktop site is another. There's a hell of a lot going on in between those two frames that we can't afford to ignore.
If we pretend otherwise we are lying to ourselves