Float centers, more so than some other brick and mortar businesses, tend to be desperate for maximizing the efficiency of their space. And float rooms would have so much extra space if they didn't have to deal with a door swinging in and out all the time. Why don't float centers do it this way instead?

Well... Graham and Ashkahn explain exactly why centers don't do this already, along with the vast majority of other buildings being made currently. It's likely a code violation and even if it weren't, it'd probably be unnecessarily hazardous to travel through your center that way.