business seats can recline fully flat and also sit up and they take up a lot of room. given that the name of the game in economy is maximizing seats in square f

business seats can recline fully flat and also sit up and they take up a lot of room. given that the name of the game in economy is maximizing seats in square footage, we're not likely to get efficiency here. the regulation is not really that the seats have to be sat up per se, but that the plane has to be evacuatable in X amount of time, and the only way to do that for your average person is for them to be sitting upright. Which makes sense; it takes a lot of time for someone to get out of a lie flat position.