Alex, despite your tender years you've just made a valid point.
One aspect of the 1985 Manchester Air Disaster which saw 53 pax and 2 crew die in a smoke filled cabin was the difficulty of evacuation due to lack of space and the bodies of pax in the way.
This diagram speaks volumes and shows why having an evacuation plan in mind puts you ahead in the survival stakes
File:Britair28m.png - Wikipedia, the free encyclopedia
Would it be right to think that any smoke in cabin incident could potentially develop quickly into far worse a situation?