I think I remember reading this excerpt from AoY... Thanks for sharing it!
Considering the benefits Kriya yoga gives one would wonder why someone would not attempt using Kriya in their meditation practice. I believe one reason is that most people do not have the patience to do several complete kriyas. I’m not saying I’m an authority on this. It is just that it requires more focus then for instance a mantra. And, the focus needs to be steady. That is why Paramahansa Yogananda gave so many other meditation techniques to prepare us for Kriya practice. I still find that my attention wanes if I do too many at my present state of development. We are fortunate to also have different Kriya practices as well, to keep our interest stimulated.