In this crisis the money supply has already increased far more than during the last crisis. But it's hard to say when this will produce inflation because we're still in the midst of a demand shock and a collapse in oil prices.
Landlords invest their stored labor—savings—at a risk and with the knowledge that they won't recoup it for some time. In creating or renovating rental properties, they aid those who can't store their labor yet—tenants and laborers.
The whole idea of government regulating so-called monopolies in order to promote competition is based on fallacies. If anything, such intervention only stifles market competition and lowers living standards.