Interesting trail and I was looking to see why BA in WTP and WT did not insist on raising blinds on LHR - RUH - LHR last week. Same crew out and back.
I remonstrated with DragonAir last year on a flight from PEK-HKG about blinds positioned for T/o and landing and, also, the fact that myriad passengers had earphones in for the same flight components.
Those that remember a BA 737-200 aborting a fiery take-off at Manchester several years ago will quickly understand the value of having blinds open to be able to assess external conditions - wind direction etc - in case of the need to evacuate the a/c. Clearly the path away from the a/c should not be into a prevailing wind...