It's this. JR is going to own that land, sell the team before he has to pay much of anything, and cash out on the Sox. The 78 going through would be a move that Sox fans should be getting behind if you could read the tea leaves.
And the other thing is, as I said before, this is further along than people want to realize. Sox are very much aware of what used to be on that land. They're aware of "the challenges" which any plot of land presents. And whoever said "Sox fans won't even drive past it", that couldn't be further from the truth. Roosevelt is already a major road in Chicago. That Target (which is literally across the street on Roosevelt is the most popular one in Chicago. There's a ton of foot traffic there as is due to bars, restaraunts, grocery stores, etc. I would venture to bet, that place would be visited (forget "driven past") way more than GRF due to location.