Alright, picture this. The Byzantine Empire is raped by both the Venetians on the west and the Turks on the east. Their empire is completely destroyed. Except... they have a small enclave on Cyprus that goes unnoticed for 100 years/turns.
Or, let's just say you're the Julii and you're tired of taking crap from those Scipii perfume-users. So you take all of their provinces in Italy, only to realize they have all of Africa.
Here's where I'm getting at...
Nations must have ALL of their territories taken from them to be eliminated, or their entire royal line must be killed. This means that factions will stay alive forever, in the most wildest of places, like Scotland in Norway. But... with a map covering a good 1/4th - 1/3rd of the world, how can CA expect European countries to honestly NOT be wiped out in Europe?
The player (or Milan...) will easily destroy a country's homeland in the Old World. This will be especially true if a country's resources and military are being exported to the ends of the earth so they can have a little more gold in their coffers. But there won't be any more coffers... except in their colonies in America, India, or wherever, where they are now surviving perfectly fine.
How can CA expect to hold to historical accuracy if things like this will easily happen? And who believes this will completely screw up gameplay?