I thought he did a decent job providing details in The Phenomena, but, you're right. He could absolutely provide more information. Did you ever listen to the most recent coast to coast am with Whitley Streiber? At one point, he states that the reason why people like himself, Jacque, and most likely the government (coughLuecough) don't give the whole truth is because concisely describing the phenomenon, revealing its true nature with no obscuration, gives it power to further enter into our reality in its entirety. So, everything is a little bit distorted and only a very small few know it as it is. I think I know what it is, based on experiences I've had. Think of it like a continuum - first there were spirits revealed to man in the age of hunting and gathering, then divine beings as our mythological capacity developed, as technology entered the mythology they became more anthropomorphic until, today, we encounter technologically advanced humanoids. Do you see how the progression of the way we understand the phenomenon tracks with the evolution of our paradigms, as a species? We're viewing interdimensional beings with a 3 dimensional lense - the lense changes in composition as our paradigm evolves, but it is still viewing the same thing. Once you've seen the thing, it's really unappealing to describe in precise detail. I don't know if it's because there's an inherent danger in doing so (think the nam shun of Enki) or if it's because it's so incredibly foreign and incomprehensible that it evokes Lovecraftian levels of wrongness.

All that being said, I am certain that a spectrum of non human intelligences exists, I've encountered my share, many before the fact of my exposure to the accounts of other people, and I've witnessed their influence in day to day life.