I believe the violations would be the larger concern by the landlords. A rent controlled property that is transferred represents a known loss that can be mitig

I believe the violations would be the larger concern by the landlords. A rent controlled property that is transferred represents a known loss that can be mitigated (and it's not worse than it is today - rent controlled). Violations represent an unknown amount and are unbounded, cannot be controlled for and cannot be mitigated easily or inexpensively... though that's part of the article (if you could do face recognition as a landlord you'd be able to alert someone about suspicious activity at apartment XYZ) that would otherwise represent some significant expenses (that would be even harder to do with rent control).