So long as the developer makes a profit, that's all that matters? Who cares if it results in a transit nightmare, that's someone else's problem. Sounds like a great way to plan a city.
Every time you mandate parking spaces in new developments, you mandate the continuation of the car-centric city model that is simply unsustainable once the population grows past a certain point. Cars are effectively being subsidized by the government in most cities. That money should be spend on transit instead.
Serious rail projects take on the order of 30 years. I think it's much more likely that people would go somewhere else, rather than endure an entire adult life without acceptable transportation options so that maybe the grandchildren would have it better.
They sure as hell don't take 30 years when they care, though. How long was it to get 405 expanded with another lane? And for all that it's now even slower than before!