A real estate business could offset income from occupied property with costs from vacant property held for speculation.
For speculation, you can let a building rot, then get it reassessed. If the jurisdiction assesses part or all of the tax bill on the value of improvements, this can drop the annual tax bill significantly while you hold. If you plan to hold for a decade or more, this can be very important. Strategically, this also ruins the neighborhood property values, so you can assemble neighboring parcels to support future major developments.
This is a long speculation game. Exemplars of the strategy include Richard Basciano who bought up several buildings in NYC's Times Square and installed adult theater tenants in the 70s, for payoff today; and the late Sam Rappaport who pursued a strategy of squeezing rent and simply ignoring building inspection violations in Philadelphia, assembling major urban core parcels on the cheap, and whose children are now selling into strong markets.
Legality: Adult businesses are kind of a grey market covered by specific local ordinances, neither exactly illegal or perfectly legal. Ignoring building violations is not legal, but the penalties are fines, not jail. It's certainly not a "nice" strategy.