There is a whole shadowy world of property owners who own poorly maintained slum property that they buy cheap, fix up to a minimum standard, and basically farm for rent at premium rates. Typically in most cities there is a cartel of a few dozen people who own a large proportion of this type of property. It's difficult to identify them as they work through shell companies.

Much of this property is subsidized under the Federal Section 8 program, which pays a "prevailing rent" rate for low income property. Often these rents approach the rates paid for luxury apartment complexes in the suburbs.

These folks need to keep the areas around their property poor and ignorant. So they work with phony "progressive" mouthpieces/lobbyists that block good construction projects using the environmental impact review process. They'll blow up issues like traffic impact, greenspace, impact on storm sewers, etc to block things like medium-density housing. (Typically, they are silent when their sponsors drop a 200,000 square foot big-box + strip mall nearby)