Because of King James Onlyists who not only insist (incorrectly) that the KJV is the ONLY valid English Bible translation out there, but also insist (also incorrectly) that the KJV is perfect.
As for those Greek texts...
Were YOU there when any of them were written? Do YOU know who wrote any of them, when and where? Do you know what SOURCES they used?
If you cannot answer any one of those questions, you have no more ability to decide among them than anyone else has.
I have done much research into the critical texts of wescott and hort and their heavy leaning on Vaticanus and Sinaiticus, I also have observed where the modern Nestle Aland text follows the Wescott and Hort superstitious worship of these 2 manuscripts, and have researched the character and corruptness of these 2 manuscripts.