One of the best ideas for solarpunk co-housing I’ve seen is Bluelightning42’s post about re-purposing malls on Tumblr. While there has been the mixed use redevelopment of the Arcade in …
Victor Gruen who effectively created the modern shopping mall, originally envisioned them as the center of a full-fledged community including apartments, schools, medical, parks, etc. Because Southdale Mall (1956) was commercially successful, the developers never bothered to implement the rest of his design and everything since has only inherited the commercial aspects. Since they acted as a de facto third place, the shortcomings never became apparent – but with the rise of anti-loitering ordinances, the deaths of the major anchors, and the shift to online shopping, malls no longer had anything to tie them to the community.
Marc Augé even called them "non-places", spaces without any sense of identity and belonging. Everything in there is just optimized for consumption and commerce. Malls are very specialised as you described, rendering them obsolete as soon as circumstances shift a little. Just speaks die the short-sightedness of their developers and the municipality that thought of them as a good idea.