That's exactly it. You have to assess the situation outside before knowing which way to run/which door to open.

Yet, there is no rule (at least I don't remember seeing USA FAs announcing or enforcing the rule in the last few years) that says window shades must be up during taxi, takeoff and landing - it could waste important time during an emergency - if you can pull the shades up at all after an accident.

I know, the fuselage might be open anyway and people probably just follow the crowd/FA's scream.