There are a lot of reasons I obsess about The American Dream (the mall and that other thing, too), and Chris Christie isn't actually one of them (okay, it's good for a few extra giggles). One is that it isn't actually difficult to build something which will attract people, but we're basically allergic to public spaces that let people do anything in them. People like to be around other people, especially when the weather is nice and there's reasonably priced food and drink to be had. It really isn't that much more complicated than that. People like to eat and drink outside around other people, and it's a novelty when it's something you can just do and not a Big Event. Sure you can throw in some shopping and activities for the kids and all that, and selling stuff obviously pays the bills, but mostly people like to get out of the house and have a place to go hang out a bit. Most people don't actually like "shopping" (though many do), it's just an excuse to wander about and soak up the atmosphere.
My urban hellhole finally discovered that people don't love tailgaiting for football games because they love football, they love tailgating for football games because they like to spend the day outside drinking and eating food with other people. Sure they like football, but tailgating is really an activity in and of itself. So now the city has lots of occasional and seasonal spaces where people can do similar all the time. Lots of these "festival" things which might have individual themes but basically are booze, food trucks, a few bands, and some arts and crafts type vendors. They're all so crowded nobody goes to them anymore.
"The mall" was always a shitty public space because it wasn't really public. Also, too, indoors. If there's really nowhere else to go on a Saturday afternoon, people will go, and of course people do need to go shopping at times. But building spaces to attract people isn't really that complicated, and gimmicky things might get people to show up once, but not over and over and over again. Novelties wear off, quickly.