How did plan creators arrive at the parking density restrictions?

I understand that the theory is that the parking density should remain approximately .5cars per unit of housing ... so I know where it came from. I'm curious though: how can the plan developers rationalize that this density can remain at such a low level, while they also approved new mid-level/high-rise development near market and van ness?

Simple math, there will be more people per square mile after the developments are complete ... and the same number of street level spaces (if not fewer). The density guideline just doesn't make sense and appears random and arbitrary. Meanwhile, my neighborhood (lower haight) is experiencing worse and worse parking problems, and we have no means to solve that problem by adding garage spaces. I think the developers just want to affect property value and actually have no interest in creating a liveable city.

Also, when I try to get answers, I'm told that the plan is meant to discourage car ownership. While I agree that this is a worthwhile goal (I haven't owned a car since 2002), I don't think that our transportation infrastructure can support this. Muni is experiencing budget cuts at a time when the market octavia plan is requiring better transport to take up the transportation slack created by the parking restrictions.

What is noble goal will make our city LESS LIVEABLE IN THE FORESEEABLE FUTURE!