I can corroborate your conjecture somewhat. My mother bought a seven bedroom(!) home from a slum landlord. He used to buy big old homes in pre-gentrification neighbourhoods and chop them into tiny apartments.
Insurers charge a lot extra for such homes because of the neighbourhoods and the supposed high risk of MURBs combined with the older construction.
So once he hit his sixth home, he stopped buying insurance and started putting money into a pool of his own. Over the years he had, in fact, needed to draw on it for things that would have been covered by insurance, but he felt that even if he broken even, the paperwork required for spending your own money is a lot easier, you just write the cheque :-)
The slumlord business model works because he's raking in guaranteed payments from the government (60-75% of those apartments are directly subsidized), and he doesn't give a shit about the buildings.
So his liability is basically limited to shoring the place up enough so that the Social Services/Public Housing people will continue writing checks, and covering the costs of emergency demolition when the house burns or falls in.
Insurers charge a lot extra for such homes because of the neighbourhoods and the supposed high risk of MURBs combined with the older construction.
So once he hit his sixth home, he stopped buying insurance and started putting money into a pool of his own. Over the years he had, in fact, needed to draw on it for things that would have been covered by insurance, but he felt that even if he broken even, the paperwork required for spending your own money is a lot easier, you just write the cheque :-)