HI ifleeplanes.
It's actually both reasons. It really depends on the aircraft configuration. But it's correct cabin crew must have a view of the cabin at all atimes when seated. So if you face forward at doors one (like on some old 757s) there's always a mirror above or on the F/D door. Same if you face aft in the rear galley (like on the 737 and some A320s) there must be a wide-angle mirrior in the galley. Cabin crew should check that it is in the correct position prior to take off and landing.
Rear facing position is by far the safest to adopt in an aeroplane for everybody, passengers included, since in the event of an impact the strain wouldn't be on your chest or front organs but on your back. A bit like Baby car seats for newborns. They must face aft in the car for the same reason until the baby reaches about 9 months.
Safer but practically impossible for airlines to make EVERYBODY fly facing the rear....the reason is self explanatory!!!
Cheers!!!
FBW
