Is this one purely for demonstration purposes? In practice I think I'd want it to be flush with the floor. As shown in the video it looks like a massive tripping hazard.
Concrete stairwells are supposed to double as refuges, if you can't climb.
Also devices that allow easier access to an apartment are more acceptable in Japan. In the US there is a much greater need for security oriented design.
If you believe what you see on television shows set in New York, fire escapes - ladders from balconies down to the ground - are common in New York. Which would make it unnecessary to explain why they aren't used.
