well, every UI is similar if you look at it that way. I mean, people without technical knowlegde will be lost in any new UI since they don't understand it and their usage pattern is based on learned moves with zero thinking. For me, if I know what software does I'll find my way to do that (OK, that won't make me PS or CAD expert) but as Gnome shell user I wont be lost with any other DE. Some I'll navigate faster than the other but I can sure any of them. Because they are all more similar then it looks. And do the same thing.
Can't say the same for my wife. Even when it comes to android that she's using on a daily basis since HTC Hero days and still I'm way faster even with her phone than she is.
One of the best example for that is new Peugeot i-cockpit. People are bashing that on every review and owners complain that it's way to copmlicated for basic things. Sure, it's not like analog buttons for everything but it's way more simpler than one can conclude from different reviews if one can think outside of the box and accept that just because something is different it's not bad.