As a landlord, I can tell you that many tenants do the exact same thing: harangue us over minor stuff that isn't even in the contract, while they're constantly

As a landlord, I can tell you that many tenants do the exact same thing: harangue us over minor stuff that isn't even in the contract, while they're constantly late on payment, disruptive, unresponsive, etc. It's human nature to hold others in an higher standard than ourselves, hence the proverb "Physician, heal thyself". By the way, your claim that "landlords that foster adversarial relationships like that are doomed to be burned even harder by tenants" is, unfortunately, not been my experience. Being lenient and understanding only got us a year of lost rent and an apartment destroyed. But you're right that landlords should uphold their end of the bargain, too.