The difference between myth and reality... One is fiction, the other is non-fiction. King Arthur is, was and always will be fiction. If Henry the VII’s oldest son had live, then we would’ve had a King Arthur. He didn’t, so we got King Henry the VIII... A murderous sob who made his daughter Bloody Mary look like... Well... Not so bloody.
That sounds like some really poor rationalization, not least because the number of executions ordered by H8 wasn’t 57K as is often claimed, and he ruled for 38 years, compared with the 5 years for Bloody Mary, whose preferred method of murdering Protestants was burning at the stake.