Because they were not considered to be human but rather Ghosts of some kind because of their pale faces. Also, everything about them was dangerous for the common people to know about at that time. Eventually, they killed Captain Cook too just like Countries on earth likely have killed little UFOs and possibly others.
So, understanding that our present world civilizations could not really survive open contact with other planets from our galaxy that presently exist and likely have existed for millions of years already.
Understanding this is important for all the people who want "Disclosure" to happen yesterday or sooner.
Civilizations presently on earth like the U.S. and Europe and Russia and China could all end within a month of this kind of disclosure in reality.
If you understand what happened when Columbus and others first came to North and South America and how whole civilizations ended suddenly it's not hard to imagine the sudden release of this kind of information worldwide could end all civilizations on earth within a month or a year.
