It's equally as profitable to cook steaks for the poor. The margin on the steak is the same, regardless of the wealth of the buyer.

This is not true for apartments. The renter holds the apartment hostage for the length of the lease, so the behavior of the renter determines the margin. Someone who leaves the apartment as it was is high margin, someone who trashes the apartment can leave you with negative margin. Even for the entire apartment building.

Reality is that people who are rich are often required to be functional, you don't get to keep the $400k/year job if your suit smells like cat urine from the 19 cats in the apartment whose litter box you never change. If you slam back 5 or 6 cases of beer every weekend starting Thursday at 3pm, and toss the empty cans and boxes in the living room until they pile to the ceiling such that you can't get to the bathroom and so you just start shitting in the corner or the kitchen sink... likewise, you tend not to remain wealthy.

Renting to a poor person allows for alot more dysfunction, and it can cost you. You can't discriminate blatantly though, but raising the price filters them out pretty well.

Poor people who don't trash apartments must not only be the majority, but a gigantic majority, of course. But there's no way to tell one of those from the assholes who do trash apartments. And landlords aren't in the fairness business anyway, so they don't care.