The same reason that health and science professionals who don't care for money at all, just an honest days wage that is, are silenced.
Imagine you could look into the world of germs and disprove most of today's germ theory that multi-billion dollar corporations depend on.
They rely on that people cannot see the truth of what they claim, to make their billions of dollars. Once people get "inside" info, like the whistle-blowers in any industry, the lies are exposed - brought out into the light for all to see the motives and the means being used - like most recently raising the price for 'needed' epi-pens astronomically just because they were the only supplier (a new owner of the company - widely exposed in the news across the country) ....
Well, while you and I might have to settle for hearing the truth, as they are so rare, others are able to see it, through a rife or rife-design microscope.
They were banned (probably confiscated and destroyed or put under lock and key) for a long time because it would have exposed what the corporations were doing as false advertising and fake science (made up test results, "tweeked" ? at least, to produce the needed results to charge huge amounts of money (extortion? , maybe) from people who thought they had no other choice) ....