Who's laughing?

Long have liked that Ira Gershwin lyric:

They all laughed at Rockefeller Center, now they're fighting to get in.

Just read Daniel Okrent's book about the creation of my fave Manhattan spot, Rockefeller Center. The book explains why it works so well -- much better than knockoffs like the Rockefeller-developed Embarcadero Center in SF.
Start with great architecture, interior art, stores and a lot to watch, including other visitors. But there's another reason: it's convenient to go through Rockefeller Center to get from Fifth Avenue over to the subway or anyplace else on the westside. So it's not just a destination, it's an enjoyable way to get from place to place.
In SF, the Westfield Centre occupies a comparable key location. To get from Union Square to Moscone Center, for example, it would be natural to go through a promenade at Westfield. Except that the shopping center isn't friendly to thru traffic -- they make it as hard as a Piggly-Wiggly to get through it. Another opportunity lost.