Even if suboptimal, revitalizing the mall as a co-working space sounds like a less-bad solution to me. Still open to practical alternatives though. ;)
If they really cant find the money sell it to developers to make condos or single family homes.
They left the major anchor stores (Target, Von Maur, Hobby Lobby), turned most of the center of the mall into parking lots, and put up a few multi-store strips around it, and it went from empty to having thriving businesses that have mostly all remained the past 16 years.
This guy has more details and took some pictures of the mall just before they closed it:
Provide the right financial incentives and a developer should be able to do it on terms favorable to the city (vs getting little/no revenue from a derelict mall complex).
Or RoboCop. You choose.
At $400/square foot to build a mall, and $XY/square foot/year to maintain it, the only thing that makes financial sense to grow in one is black market marijuana.
For example: I used to work at GoogleX's "San Antonio station", which was a converted shopping mall, and it had great lighting, even on lower floors.
With multiple employers in same building, you'd also have many more socializing options -- including random colleagues who drop by to run errands.
Besides, what would you suggest instead -- let them turn into suburban blight?!