Is it Really Sleep Paralysis?

Lately, I have been wondering if it is really valid to be explaining away the "Old Hag" that pays nightly visits to innocent victims during their slumber. Is it really fair discount the thousands of reports of this experience and merely explain that it is sleep paralysis?
  I have been wondering this for several years. Wikepedia has the following definition:

In addition, the paralysis may be accompanied by terrifying hallucinations (hypnopompic or hypnagogic) and an acute sense of danger.^[9] Sleep paralysis is particularly frightening to the individual because of the vividness of such hallucinations.^[8] The hallucinatory element to sleep paralysis makes it even more likely
that someone will interpret the experience as a dream, since completely
fanciful or dream-like objects may appear in the room alongside one's
normal vision. Some scientists have proposed this condition as an
explanation for alien abductions and ghostly encounters.^[10] A study by Susan Blackmore and Marcus Cox (the Blackmore-Cox study) of the University of the West of England supports the suggestion that reports of alien abductions are related to sleep paralysis rather than to temporal lobe lability.[1

A few questions that have been weighing in my mind in my research to this phenomena- Why do millions of people actually report the "Old Hag"? If this is some kind of hallucination, isn't it rather strange that so many people report this? While I do think sleep paralysis is valid, I do not think that you can explain every experience away with this cause. Also, there are documented cases that people have had to have their home exercised because the "Old Hag" was a nightly appearance.

I am sure some of you are wondering-What do I think the Old Hag is? Personally, I have had an experience, that could be classified as Old Hag. I did not see an Old Hag, but I was in bed, I could not move or talk, and the bed was shaking uncontrollably. I do think that it was an entity that did not want me in the house. I have not had this experience again. It happened once. I would classify this as a spiritual paralysis. I feel that the Old Hag is actually some type of spirit vampire. I believe this is something that wants to suck the life force out of you because it needs energy to do its evil. The Old Hag is not positive. It tries to attack what it thinks to be are weak and vulnerable people, children, and maybe people going through weak times in their lives.