I think what Blue Star complains about is the lack of a "realistic" procedure in a realm's nobility towards a threat. They vote to decide if they leave or not, and the "yes" option means to leave behind land, culture, etc. I'll say what I think about it, comparing it to Europe in Medieval times.
1. Comparing to real world, the colonisation of Dwilight started less than 30 years ago, if I'm right. It was colonised by nobles (players), who formed their realms to rule upon a civil "native" population.
2. That means that, from a real word perspective, nobles pretty much arrived to a continent to stablish their lands and get profit of them. A lot of them couldn't even RP that their families were natives and entered the Nobility, since maybe a player created his first character in another Continent, so his home is out of Dwilight.
Think of the Normans when they took control in England.
3. I'm sure you know that not all nobles in a kingdom or realm have decided to fight 'till death to protect it from a foreign threat when they knew it would be in vain. Even if it was the land of their ancestors. Think of the conquest of the remains of the Byzantine Empire. When Costantinopolis fell, many of them fled to other Christian kingdoms, even being Orthodox. Okay, it was their capital. It leads us to point number 4.
4. They're monsters, dude! Even if nobles in BM has fought against them constantly, realms are overwhelmed! Put a Dwilightean noble's shoes on! You're a highborn who takes profit on the work of native peasants, which are assimilating your culture because it's been imposed by their rulers, in the case of Barca, less than 20 years ago. You will fight hard to keep your lands, but if hordes of howling monsters threaten every corner of your realm, won't you make your valises and try to find a new land?