Seriously though it is worse then killing them. Now that you put it that way we should just round up all the people in prisons and use them for medical experimentation. Like any government that takes it upon themselves to 'disappear' people in the night but in a sick way worse because those 'disappeared' get replaced by a Institute drone. Killing people who they decide are a problem is still wrong.
If they were only taking 'bad' people that doesn't change the fact that they were replacing people.