Because people’s thresholds for awesome have not opened and expanded large enough to hold something of this magnitude.
Annnddd, let’s count the reasons: it is channeled information; it is sourced from discarnate planetary civilizations in higher dimensions; the material is dense and, especially in the case of Ra, the prose can be quite technical, clause heavy, and filled with jargon; no “proof” is offered beyond the innate strength and logical consistency of the material itself, its congruency with earth’s perennial philosophy, and its appeal to our highest ethics; L/L Research doesn’t market or advertise; much of the planet is still battling over cultural, ethnic, and religious differences; it calls one to the highest possible self-responsibility in the disarming vulnerability that all is the Creator and that there are, ultimately, no enemies or victims, not to mention no right or wrong; and, the big one, if you want to use the word, aliens. (For some reason, most people on this planet don’t have an established context for accepting words received through telepathic contact with beings from other planets and dimensions).
Also, even if all the above were not stumbling blocks, it is level of teaching that is still a few steps beyond what those in third density need to simply make the Choice to serve. It is geared more towards adepts, those burning with an uncommon strength for seeking the One Creator. And, though unknowable, it likely appeals mostly to wanderers. Though naturally many who feel they are not wanderers also appreciate the Law of One.