> Cars are filled with people and people work and spend money.

You're conflating people with cars. You want people and you're assuming that all those people must be attached to a car. There are other ways to get people to be populate an area which brings me to my second point...

> If you rip out the parking you won't get a vibrant walkable downtown

You will if you build a lot more housing in that area. If thousands more people are able to live right there then of course it'll become more vibrant. That parking garage could be home to hundreds of people. Instead it's temporary storage for cars. The problem is that suburbanites are going to fight tooth-and-nail to bring their cars. So what you get is cars.

If that's what you want, so be it. That doesn't sound like a vibrant place if everybody has to drive a car to get there, though. It's traffic by design.