It is much easier to transfer land to your political cronies or business associates when the time is right than to siphon off cash from the city treasury.
In real estate deals there are a lot of grey areas that no one thinks to look at, while if you steal cash, that's very easily spotted. So there is really no advantage in converting these properties into cash that the citizens of Jacksonville will only just demand spent on things like "parks" or "schools" or "police".
When the Mayor runs the city for the benefit and amusement of his family, selling that land suddenly does not look so good, from his standpoint.
So, just consider these properties as "patronage banks", that at some future time will grease the wheels of business. Unfortunately, it probably won't be the city's business.