Have you looked at the population spread of the Roman Empire? Rome had people, the rest of the empire was predominantly to the East/South. Rome was Mediterranean, not Western European.
The first map shows roughly thirteen million people in non-Italy "Western Europe" and roughly twenty two millions in the non Western Europe parts. Wikipedia has an actual population density map[1] that highlights my point. Even in traditional "Western Europe," the population is predominantly Mediterranean. It also has a list of the most populous cities during the peak of the Empire, largely outside of Western Europe.
So about half the roman empire (including Italy) was in Western Europe? Of course the Roman Empire extended further (and longer in other regions), but saying Middle Age's Western Europe doesn't include large regions that were previously part of the Roman Empire seems strange to me.
Novacole said “Rome isn’t Western Europe. So western Europe’s entire history is a “dark age” before the Age of Enlightenment.”
That seems to imply that Rome isn’t part of the history of Western Europe at all (and neither did the Renaissance happen in Western Europe, apparently).
Though I can't make out Novacole's exact point, I would assume it was more about how it is incorrect to say "there was a dark age after Rome" as the dark age only impacted a part of the still existing Roman Empire.
https://aaron7roberts.files.wordpress.com/2015/04/roman_empi...
https://en.m.wikipedia.org/wiki/Demography_of_the_Roman_Empi... also shows larger populations in the “Latin West” than in the “Greek East”.