The City cannot legally force the developer to include low-income apartments. The City "allows" whatever the building code says is allowed. This is how a civilized society works, laws are made and then decisions are made in accordance with those laws. We all play by the same set of rules. If you owned this site, you could build the building of your choice within the parameters set by the zoning code, just like this developer is doing. If your business plan was to build a building and cater to low-income tenants, then that would be your choice. This developer is choosing otherwise, and it's none of your business what he does with his own money if he is following the rules, which he is. You may disagree with his business plan, and you may disagree with how he chooses to monetize his real estate, but in both cases these choices are absolutely none of your business.