> If government can tell you who can stay with you, regardless of any private transactions or agreements you make with that person, then government has more authority over your living space than you do.

Fire marshals have limited the amount of people you can have in a particular building for more than a hundred years.

I don't know the rationale in this case, but there are very good rationales for government to have more control of your house than you do in some instances. Mandatory fire suppression systems can end up saving not just your apt unit, but your whole neighborhood.