In comics and movies, it is usually shown that when the protagonist encounters such a situation, his first action is to go beat up the guards and rescue the people who are being forcefully dragged to their deaths.
However, those films always fail to show the greater implications of this action.
The main thing is that the government also doesn't want to throw them out, but for the survival of the majority, they have to make this sacrifice.
By exiling these people who give no returns to society, the government is fulfilling many goals at once.
Not only does this serve as a warning to other people that they need to work hard if they want to live in their safe houses, but it also quells the massive monster siege.
Once the monsters eat their fill, they don't attack the cities like crazy, and massive monster sieges don't happen.
