How dirty will you let your Tenant be?

[Nathan Gesner]

We all have different cleaning standards, but some people are just filthy! 

Below are images from an actual apartment that's been occupied by the same tenant for almost 30 years. He pays 15% below market rate but has never been late once. The yellow glow is from cigarettes, not my lack of white balance. The last picture shows how even the items stored next to his bed are covered in thick dust.

Would you allow him to stay? Would you force him to clean it up? Would you kick him out and renovate?