It's not so much the owner's financial situation, but rather that it'd be cheaper to build new homes than to retrofit a ten floor+ building's plumbing.
You'd also have to install a bunch of showers, which could be a significant problem on its own.
And then there's the increased amount of sewage, which the building might not be able to handle - even the local sewers might not be equipped to handle the uh... Load a large commercial building would generate with 24/7 occupancy vs 8/5 occupancy.
The reason you don't see folks converting commercial spaces into residential isn't because it's not wildly profitable, but because building new purpose-built residential buildings would be cheaper than a conversion for anything other than one or two floors.
