I've read those passages many times from Yogananda's autobiography. He is simply saying that there are good astrologers and there are bad ones. This is what you'd expect in any field I guess. But still you must realize that those reassuring words are not proof of astrology. It may in fact be that astrology has fallen into disrepute because of the lack of skilled practitioners. Yet, it seems there are plenty of people who would have the aptitude for it. An Einstein for example, or a Newton, or the like, would be totally capable of reviving the lost art - wouldn't you think?
It almost becomes a circular argument when you consider that it might be the other way around; the worlds mathematicians and scientists might not be studying it because it is doesn't measure up to modern scientific standards, rather than vice versa.
You must admire the fact that he admits, "it's not a matter of faith." Well, one should take up that mantle. But for most that I see, it seems it is precisely a matter of faith.
No more then science is matter of faith. As a point in fact science changes and evolves over the years much more then astrology does. So can we really have faith in scientific findings when many of them become outdated with time or at the very least they are found to be unusable in the face of new discoveries. Are we bound by the discoveries of science? Only the foolish are. There is little if no lasting evidence of the proof of science. A Newton or Einstein helping astrology may be like putting physicists in charge of the gym or psychology department at a university. Leave them to their own fields and leave Carl Jung to his. We have seen the remarkable achievements of science in the atomic and hydrogen bombs. It is fortunate that astrology cannot be used in such a menacing way.