Boston 4K Real Estate Development - New Homes Condos Apartments - Why Not Develop this JP Site???

Check out this massive chunk of land (by Boston standards) along the Arborway and near Morton St W close to the Forest Hills #mbta #trainstation

There is an old building looks like a decrepit military office like I saw back in the day on an Army base. it was the old T Hq. Why not make a massive development here so more people could live close to the T in JP and right next to Franklin Park and the Arnold Arboretum????