It's true enough that the Penobscot Building probably has more than 100,000 sq ft of vacant space. None of it is set up for a large employer workplace though. Lots of renovation would be needed and with 1920s floorplates, it would be expensive. Couple these issues with the awful track record of the building's current ownership and it's understandable that QL would not be looking to expand there. That's too bad.