Which part is the myth -- the notion that the Middle Ages were crap, or the article debunking that?
The article states that the Dark Ages were only "dark" because some scholars believe that Rome represented civilization, and that its downfall led to the rise of savagery in Europe. In fact (which the article tries to show), Europe was freed from the conquest of a barbaric civilization. Of course there were some minor wars between kingdoms after the fall of Rome, but at least the Europeans were free to have them. IMO, if Rome (in the west) hadn't fallen, we would still be living under barbaric Roman rule.
"I absorb energy like a sponge everywhere I go. It allows me to see the world and my purpose in it." Zak Bagans, Ghost Adventures (INFJ)