People say that because outside of modern times in the first world, landlords = the mafia. Without expensive police, landlords have to enforce their own rent. So if you’re socialist or any other political movement bad for landlords, they probably make up the biggest paramilitary force in your country and if you don’t decapitate that chain of command fast you get dumped in a cave with 20,000 other skeletons.

And even in a first world country, the police manhours dedicated to evictions and the private security industry funded almost entirely by landlords is something anybody who wants to deal with housing prices is going to have to worry about.