In my opinion, AngularJS should not be seen as a complete replacement of what already exists nowadays, it's just an additional tool and should be used only when appropriate (the right technology for the right task). Making a full website from scratch with AngularJS and creating all the useful features already available in the current WordPress ecosystem (themes, plugins, responsive design, ...) would just be too time consuming for a website providing examples and would not give much advantage. I'm the site creator and since I don't work on it full-time, the time it takes to make it is an important factor. I just hope I can provide some useful information on AngularJS. This is just my opinion of course :-)