Who killed Market East? Well let's take a look at the big box, discount department stores that typically provide the scapegoat for the death of the American Main Street. After all, Market East is the historic model for every Main Street in North America. The answer might not be as simple as blaming Walmart.
First of all, Walmart didn't kill small town Main Street. That's just how activists and protesters remember it. Small town Main Street died 30 to 40 years ago, before the Walmarts and Targets were what they are today, around the same time and for the same reason big city downtowns died. Small towns started becoming sprawling, independent suburbs, with strip malls, shopping malls, all catering to the car. This is even more evident in small towns where everyone has and always has had a car, making downtowns even more useless than big city downtowns, particularly during the 60s and 70s when suburban sprawl was en vogue.
Once this cultural mindset was well established and absolutely nothing remained in these small city's downtowns, discount department stores began to grow, and these megamarts became the nail in the coffin of already dead Main Streets. The difference between, say, Scranton and Philadelphia is the fact that Philadelphia, as well as a number of major cities, managed to retain a population significant enough to warrant the retention of a practical public transportation system and walkability, which is why Targets and Walmarts haven't killed downtown Chicago, New York, Toronto, DC, etc.
It's easy to blame megamarts for killing small town business, but more fault is on the part of a lingering mid-century culture of convenience in lieu of quality. Most of the successful, post-industrial cities manage to walk a sustainable balance. And Philadelphia actually did that by using that discount element to combat suburban competition by putting it right on our Main Street.
As much as we love to hate it, anyone who's been to Market East can tell you that the big box, discount chains are the only thing keeping Market East alive. And Target aptly placed in the Disney Hole might introduce the competition needed to put products back on the shelves at K-Mart and encourage PREIT to start implementing some of these proposed changes they claim to be so excited about and actually improve our Main Street.