I think it requires a change of mindset. I've been using Linux exclusively on all of my machines since 2004. I started with KDE and then switched to Gnome 2 and finally Gnome 3. Everything looks clean and normal to me. On the other hand, every time that I need to use Windows (even Windows 10) it feels strange. So I guess it's a matter of perspective.
You make a good point. Sounds like we are at a crossroads: do we cater to what's familiar or are we trying to attract new users (like this post aims to do)?
In my opinion, there is no reason the design can't be made to look better while still maintaining the familiarity (like OS X mavericks did, for better or worse).
