I am not a firefighter nor do I have experience in the biz. I just don't see why a firefighter would ever want to walk on a roof in a bad fire. Every room has a window and provides better access to a fire without endangering a firefighters life. The roof is one of the most dangerous places to be in a fire because if the fire has weakend the roof the firefighter could be a step away from falling to their death. It's much safer to hang the ladder over the roof and spray from there.

Anyway, dumb code in my opinion which is why it isn't the norm.