Businesses used to absorb huge expenses to improve their product or service and stay competitive. There simply isn't enough competition in business anymore. In this case the competition is other available rental properties in the area. But since there's not much competition in this or other industries now, the general sentiment has become "all expenses must be passed on to the consumer and all savings retained by the company", and it's pretty fucking frustrating as a consumer.

They’re not going to be able to rent apartments without air conditioning anyway unless it’s a slum. It’s too hot now. And if they do, they’re going to end up hurting someone and getting sued. So the rent is going to go up either way.