If there are no windows opened, it doesn't make any sense to have the Windows view as default when we go through Activities.
Edit the file
Search these lines (Line number = 469) :
Change them to :
And, Save and Restart Gnome-Shell.
Change the method _switchDefaultTab() for this:
and add the next code line: "this._activeTab=viewTab"; in the method addViewTab():
all in the file "viewSelector.js".