Jantje
Thank you for saying loud what I'm thinking actually. This is just another example of what I've already pointed at, the lack of consideration and lack of respect towards Arduino contributors from the Arduino team .
Anyway, the question is now: How to use standard tools as GCC to compile a sketch with the new library structure?
The Arduino IDE avoids the issue by performing under-the-hood work. I could have tried to mimic that on Xcode but, let's face it: Wouldn't be easier to consider a sketch as a plain C++ project?
When Arduino is going to understand that, behind the limited IDE, there's a framework worth considering and promoting?
Now, there are so many interesting boards outside, cheaper and more powerful, ...