Because such a rule is clearly anti-poor. It's the same reason why number coding is a bunch of BS. Those who can afford extra cars would just buy more cars. The guy who barely could pay his Wigo are the only ones truly affected.

Speaking from experience, the apartment we used to stay at didn't provide any parking spaces, so tenants had nowhere to park their cars but in the streets. Potential landlords should be required to provide a lot (or build one on their own land via basement) before being allowed to rent out spaces. But nope, elevator nga lang na dapat you should have when building a structure with 3 or more floors nakakalusot sa building inspection.