I think there is still a fair point. I'm quite familiar with AngularJS and writing quite advanced directives and I would agree some of the APIs are not as user-friendly as they should ideally be. Couple that with limited documentation and guidance and you have quite a steep learning experience.
I partially agree, directives are not easy to learn, and there is not enough good documentation or literature on how to write them well. However, I have found the api to be very expressive , concise, and flexible once mastered. I can't say the same for most real languages I work with everyday.
Bottom line, things could be better.