You could similarly run the police at a profit instead of being a cost center by gifting 100 hectares around every police station to the police, and have them collect rent on it. That doesn't make sense either.
For one, it creates a perverse incentive where the government can't let property prices fall for the common good least their public transport (or police) services would go out of business.
Hong Kong famously has a problem with this. It's a relatively low-tax regime with absurdly high housing prices, because they raise a much larger part of their revenue by taxing land than most other similarly developed areas.