The author did not even talk about why these laws are in place, so I think it's worth mentioning that these laws are there to prevent slums. I'm not saying there's no place for them, but "busybodies and do-gooders who prevent people from using their own property" is extremely dismissive of efforts to solve a huge problem that existed in the 19th and 20th centuries. In fact, it sounds like the author would argue that being a slumlord is the right of property owners.

You can prevent slums without outlawing this type of housing, they just need to be actively managed. Require landlords via regulation to keep up maintenance and evict unruly tenants, and actually enforce those laws.

I think you just push the problem away, now you got homeless people.